It would be fun, but really tough, and occasionally impossible.

Not all of the origins of the names of neighborhoods are known. The one I've always wondered about was the "Tender Loin"/"Tenderloin" district of SF. There are a lot of anecdotes about the origin of this name [1] but no one has a definitive answer.

[1] http://en.wikipedia.org/wiki/Tenderloin,_San_Francisco

I'm going to add a version of this soon! Not overlays, but at least popping up the neighborhood name histories when you use the "Jump To" neighborhoods list in the corner. I didn't make it too high a priority since most of them are either duplicates of street histories (e.g. Cole Valley, Upper Haight, the Mission) or self-explanatory (e.g. the Sunset, Chinatown, the Marina).