I met a few at Emerald City Comic-con a couple weeks ago (the one with Tara Strong and the giant Twi). It's pretty cool meeting them, and wearing a brony shirt helps with that. We have quite a few bronies spread around the Seattle metro. area, and some of them randomly meet other bronies from time to time (Seattle beeing a geeky city could contribute to that as well).
My college, however, has only a few.