This would be a cool report for github or bitbucket etc to provide across public repositories. Especially when combined with any basic demographics. Of course, I don't think they collect a ton of demographics today so not sure how valuable it would be.
I bet you could build profiles on people and predict changes in their patterns based on life events and other changes (kids, marriage, aging, divorce etc). Of course, I bet many people would find that a little creepy, but the data side of it is pretty interesting, at least in my head it is.
Many times I have been stuck with a specific programming problem till late at night. The next morning, the code or the algorithm was in my head, all ready to be written down.