Which pair of mathematicians has the most joint papers? I was searching on MathSciNet recently for a certain paper by two mathematicians.  As I often do, I just typed in the names of the two authors, figuring that would give me a short enough list.  My strategy was rather dramatically unsuccessful in this case: the two mathematicians I listed have written 80 papers together!
So this motivates my (rather frivolous, to be sure) question: which pair of mathematicians has the most joint papers?  
A good meta-question would be: can MathSciNet search for this sort of thing automatically?  The best technique I could come up with was to think of one mathematician that was both prolific and collaborative, go to their "profile" page on MathSciNet (a relatively new feature), where their most frequent collaborators are listed, alphabetically, but with the wordle-esque feature that the font size is proportional to the number of joint papers.  
Trying this, to my surpise I couldn't beat the 80 joint papers I've already found.  Erdos' most frequent collaborator was Sarkozy: 62 papers (and conversely Sarkozy's most frequent collaborator was Erdos).  Ronald Graham's most frequent collaborator is Fan Chung: 76 papers (and conversely).
I would also be interested to hear about triples, quadruples and so forth, down to the point where there is no small set of winners.

Addendum: All right, multiple people seem to want to know.  The 80 collaboration pair I stumbled upon is Blair Spearman and Kenneth Williams.  
 A: Perhaps Hardy and Littlewood?
A: E. Cline, B. Parshall, and L. Scott have 28 papers together, spanning 35 years or so.  Just one example of a triple...  
A: Another thing that is surprisingly rare is a long term collaboration within a single math department. Erwin Lutwak, Gaoyong Zhang, and I, all at NYU-Poly, have a long term relationship that has yielded about jointly authored 21 papers so far, some with an additional author.
A: We get 135 matches for "Author=(Jimbo, Michio and Miwa, Tetsuji)" in mathscinet.
A: This is a frivolous item solely to demonstrate the pitfalls of running MathSciNet searches and working with large datasets:
Type "Wang and Zhang" in the author field and get a list of 2417 items. Li and Wang are close contenders with 2300 total. I wouldn't venture a guess how many collaborations that represents!
A: How about Ravi Agarwal and Donal O'Regan with 445 joint journal publications on MathSciNet?
A: 
      I.M.Gelfand and M.I.Graev: 119 

Disclaimer: For the purposes of this answer, the paper count is the number given by MathSciNet, which includes book translations.
A: Sergio Albeverio and Raphael Hoegh-Krohn have 98 papers together
according to MathSciNet. 
