There's a few of us, but we like to hide with work and everything else going on. I'm 32 & male, and know a few women in their 20s/30s.
Most events seem to be in St. Pete, though. I'll most likely be at 1st Dance this Friday, but Bayou seems to be the hot spot (too crowded for decent dancing, but good for socializing). Both are on 66th street.
I haven't been to these yet, but if you're looking for something in T/B/S, you might try:
M - Dance with Class / Bradenton W - Wilson's Dancesport / Sarasota H - Easidance / Tampa (Carrolwood)
Heads up: Dance With Class is changing to an Arthur Murray studio. I'm not sure when that's going to happen, but you might want to give them a call before popping in, in case their calendar takes a hit.