Digital pen for math: your experiences? This question is similar to this question but with a slightly different purpose.
For many of the reasons presented in that question, note taking can be useful but tedious. Similarly, this question addresses the difficulty of keeping track of notes(research notes in that case). Myself, I have been amassing pages and pages of notes from courses and seminars. The really important ones I attempt to Latex but often get lazy. My question:

Have you tried using technology like the digital pen for taking notes during math lectures? If so, what do you think? If not, discuss your thoughts on this.

In general, I am just trying to get a feel if it would be worth buying one for my classes (particularly seminar).
A few notes for those of you too lazy to look at the website of the pen:


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*The pen records everything you write and uploads it as a image/video file into a computer.

*The pen also records audio synced with your writing, so you can play the notes as a movie with the audio accompaniment.

*The pen also writes in regular ink in a notebook, so you also have a hard copy.


While fairly different, those with experience using a tablet PC should also feel welcome to post their experience, since the outcome of the digital pen produces something like that of the tablet, just with some added functionality.
Thanks ahead of time, today I nearly bought one, but I thought I would ask here first. 
 A: I have invested in an IREX Digital Reader DR1000. The sum total of its features and shortcomings appear to be ill defined, somewhat the sum of a conditionally convergent series. So I really have developed a love-hate relationship with the damn thing. Let me get the negatives out of the way first:


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*It's way too expensive. In fact, I wouldn't have bought it if it weren't for the fact I am on sabbatical and need easy access to piles of papers without the paper.

*The battery life is too short, definitely shorter than advertised. A couple hours is no problem, so it's good for note taking in lectures. However, it couldn't keep up with a full day at a conference. Also the battery is not user replacable.

*It's too easy to ruin the charging connector if you try to use it while charging. In fact the whole device is a bit too fragile.

*The software is buggy and crash prone (but not horribly so). There have been software updates, but they are too rare and don't fix enough bugs. Also it takes a couple minutes to boot, which is bad if the device crashes while you're taking notes in a seminar or meeting.

*The digitizer is a bit off, enough so that drawing nice pictures is impossible. (Rough sketches work okay though.) It's especially bad near the edges.

*Screen refresh is slow (but that is inherent in e-ink technology).
On the positive side:


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*It can read PDFs, and you can annotate them and merge your notes and original PDFs together into new PDFs.

*Big screen, so reading papers an the device works pretty well. And it's pretty much like reading on paper. (But physics papers in two column format on big pages can be problematic.)

*It uses an SD card for storage. I have a 16 GB card in the device, which is silly given that I have barely managed to put one GB on it so far.

*Open software architecture, so third-party software is possible. For example, xournal has been ported to the device. Also, the database format is semi-documented, enabling third party merging software (which is needed because the supplied software is windoze only).
That's a shorter positive list than negative list, but the pluses are bigger than the minuses, so one comes out about even. (Forget what I wrote about conditionally convergent series. It was a joke, but half serious.)
There are lots of other readers on the market, and many more coming, but most of them are geared towards book reading (prose, not science), so they are typically smaller, and many of them have no note taking capability. But more are coming. Hopefully, with time the price will come down and these things will become more attractive and useful. I certainly am hooked, despite the price and the shortcomings.
Oh, almost forgot. If interested in the DR1000, look in the DR1000 forum at http://www.mobileread.com/.
A: I have some experience with both the situation posed by the question and Matt Noonan's modification in the comments.
Note taking in seminars: At a recent conference, I took notes directly on to my computer using a graphics tablet in conjunction with the program xournal.  I have gotten a little frustrated in the past at having stacks of notes from seminars that are virtually useless to me because I'm rubbish at organising them and finding them again.  The main benefit of writing them directly on to my computer was that I could then add the files to my reference database (refbase) where I could store the meta-data in searchable form.  To emphasise that point, it is the meta-data that is searchable, not the information from the original talk.
I found a few other side-benefits from this method.  I was slightly faster in writing on a graphics tablet than on paper; I think that that is to do with a different posture and the fact that to go from looking at the computer screen to looking at the board is quicker than going from hunched over paper to looking at a board.  This might not be the same for something like a digital pen, though.  I think I was also faster because I was less bothered about what my notes looked like - when writing on real paper, I try not to waste paper so if the lecture is getting near the end, I'll cram the last bit on the small bit left of the current page rather than start a new one; on the computer, I just make the page bigger.  It's also easier to correct things, and to add more space in the middle of something already written (when the lecturer goes back and adds yet more symbols to the diagram!).
The only drawback at that conference was when my computer ran out of battery power 5 minutes before the end of the seminar and I lost the whole lot because the program didn't have an auto-save feature!  (I wrote one that evening - isn't open source wonderful! - but I see now that the latest version of xournal as auto-save anyway).
Another drawback is simply the amount of desk space that this system takes up.  I couldn't do this at another recent conference because it was in one of those auditoria where there is a tiny side desk which forces you to write on postage stamps.
I did think of trying to combine LaTeXing seminar notes with a graphics tablet: the idea being to have a LaTeX document in to which you type the majority of the notes, but then overlay diagrams (or other annotations) with the pen.  While I think that this would be feasible, the software needs a little tweaking for all of this to work seamlessly.
Incidentally, decent graphics tablets are extremely cheap (I got mine for about 35 quid), and it doesn't take much to get used to writing on a different place to where the text appears, so if you're not sure but think it's something you'd like to try, I'd recommend a simple graphics tablet over getting something more expensive in the first instance.  Also, a graphics tablet is great if you want to put fancy animations in your talks.
Giving Seminars/Lectures Using a Beamer+Pen: I'm now in the course of my second course doing this.  I prepare the lectures using LaTeX+beamer but when I give them then I have a graphics tablet to hand to make annotations as necessary.  Sometimes I leave whole problems to be "done live" - by the students, that is.  The first time through, I used my graphics tablet and xournal.  This time, the lecture hall that I'm in has a PC with a "write-on screen".  Unfortunately, it runs Windows but fortunately, there's jarnal.  There is a "new page" facility which brings up a blank slide on which you can write whatsoever you like.  After the lecture, I put the annotations on the web page for the students.
I should say that there are several reasons that I've switched from chalk to presentations for lecturing.


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*I give better lectures/seminars when I use a computer than when I use chalk.  This is (I think) because it forces me to prepare the whole seminar/lecture properly in advance and not think "I know how to do that" without carefully checking that I really do.

*Chalk dust irritates my skin.

*I teach in English but my students listen in Norwegian.  If I gave the traditional "copy down everything I write on the board" lecture then the lag time while I waited for them to copy stuff down would be too great (I mean that the time that I assign for the students to catch up with copying down and be ready to listen to me again is significantly longer because they are reading, writing, and hearing in a non-native language).  So I make the notes available in advance so that they have a baseline of what I'm going to say and can add to it as they feel the need.

*I can actually look at the students and see their reactions while I'm lecturing instead of spending half the time looking at the board.  That means that I can be far more reactive in what I'm actually saying.
The main drawback is the increased preparation time.  But, due to 1, I'm not sure how much of that is because it forces me to prepare properly and how much is due to the nature of the preparation.  An additional benefit will be that I have much less preparation to do next time I teach those courses (I say "will" because I've yet to repeat one of these courses.  Perhaps I should say "hope").
You can see what it all looks like by looking at the course webpages for these two courses, they are here for the completed course and here for the current course.
Note: I have lots of macros that interact nicely with beamer and make life considerably easier for myself.  I also ended up hacking xournal a little to make it better for note-taking.  Same again for refbase to make it suitable for mathematicians (it was written by geologists).  I'm happy to share any of these modifications, of course.
A: EDIT: After buying a neo smartpen and using it for 6 months or so I have a few more comments.  First, the smartpen eventually broke like every other one I've ever owned so if you aren't super careful with your pens be on guard.  Secondly, it just wasn't worth the trouble.  None of the software accurately transcribes math symbols, the tagging and searching systems suck for math so at the end of the day I just paid more than a hundred bucks for a system which was about as good as just photographing my pages with my cellphone once I write them.  I was a big fan of this idea so it's too bad but I'm going to try one of those digital pads for drawing next.
I used to use a livescribe pen years ago (perhaps an echo) and it wasn't very convenient.  The biggest problem at that time was that handwriting recognition was utterly terrible and thus the resulting notes were completely unsearchable and there was no real convenient way to synchronize in a way that didn't perfectly match up with the notebooks (if I accidentally did work on Martin-Lof randoms in the notebook for REA sets I couldn't move those two pages over to the appropriate place in a way that didn't get messed up on next sync).  Not to mention the app sucked.  However, both the actual writing capture and the audio capture worked quite well.
My conclusion was that for me it was more a way to make my research notebooks extra cool and special and it wasn't actually useful but that had I been the sort of person who took notes at talks or classes and went back to look at them it would have been mildly useful and could have been super useful with better handwriting recognition.  A pen which combined handwriting recognition with some kind of latex recognition engine would have been very useful.
I'm thinking of buying another smart pen now that the tech has had some time to mature and my advice to anyone else considering this is make your buying choice based on the app, third party tools/api, notebooks/printable paper and pen quality rather than the pen tech.  At least assuming it has basic functionality.

Note that after doing a bit more research I see that livescribe hasn't changed or even doubled down on many of the things I found frustrating about their system.  Their notebooks might be fine for taking notes in class but I want something that's both nicer and full sized for my research and the best they can do is their executive notebook which is both unimpressive and comes in only two colors.  To be fair to livescribe their pens seem better equipped (memory) to record audio but I don't use that feature.  Also they support export directly to onenote (as pdfs) but only seem to support auto-sync to evernote and even there you seem to need to tap sync.
Worse, rather than fix the issues with their API they've removed developer access entirely and (though I haven't fully checked this).  I'd like a smartpen which I can at least dream of having math recognition added.
OTOH I've been quite impressed with what I've seen of the neo smartpens.  They may lack a mac desktop app but they have a published API on github, a very nice selection of notebooks, seem to support more options for exporting content (e.g. svg) syncing (auto google drive) and advertise the ability of their software to regroup pages in dynamic notebooks.  I'm going to purchase one today and if anyone wants to know how it worked out comment on this answer to remind me to come back and update it.
Moleskin doesn't look bad either but my understanding is it's basically a neo smartpen underneath and I couldn't figure out from the website if it's fully compatible or you are stuck with a few (really nice!!) smart notebooks from moleskin and if it's not fully neo compatible I don't want to be locked in to such a boutique option.
