Apparently that's quite regional. I was corrected a few weeks ago because I called a pair of cross-trainers "tennis shoes" - where that person was from "tennis shoes" is much more specific than I understand it.

Yep.

http://www4.uwm.edu/FLL/linguistics/dialect/staticmaps/q_73....

What region might that person have been from?

I grew up calling them all "tennis shoes", though I don't think I ever met anyone who played tennis. "Sneakers" was a secondary term.

I want to say they were from Philadelphia, but I'm not 100% sure.