I'm interested in collecting real-world examples of probability distributions, and heuristics for when a probability distribution might apply.

For example:

Stock

*prices*are often modeled with lognormal distributions, assuming stock*returns*are normally distributed. More generally, lognormal distributions often apply when there's a proportional effect going on; that is, when the change in object X is proportional to object X's current size.If your data is skewed (e.g., prices are skewed to the right, since they're required to be positive), then a lognormal distribution might be good to try.

ask a question, then flag for reopening. – Scott Morrison♦ Dec 11 '09 at 2:01