^^hahaha, but seriously...do it. Just make sure they're not with the guy benching 250 next to ya.

Don't use multiple machines or whatever at once. It drives me nuts when I go to a machine and a dude from across the gym comes over and tells me he's using it, and then goes back to the other side of the gym to use another machine. In that situation, I simply ask politely if I can jump in between sets.