In no particular order:
1. Men at the gym should be required to wear shorts of a certain length-at minimum-to the knees. Anything else is just...gross.
Addendum: This also should include ladies. Their shorts need not be knee length but I don't really enjoy seeing the lower curve of your buttocks while I'm working out, no matter how skinny or fit you are. Cover it up ladies. Cover it up.
2. Men in the weight room will look at a group of girls working out who have the audacity to talk/laugh/enjoy themselves with a certain degree of condescension and disdain. I paid to be here too boys. Get over it. Just because I am not grunting and puffing like a locomotive doesn't mean things aren't getting toned.
3. If you look at the whole crowd in the cardio room for long enough, much like a Magic Eye picture, their bodies will begin to move in a common rhythm...magical. Sweaty-but magical.
4. It should, in my opinion, be illegal to work out in any of the following: velour suits (my God the sweat!), jeans (on the treadmill, for shame), shoes with no socks (need I say more?) and any variety of slip on canvas shoes (i.e. Toms etc.).
5. Singing along with your iPod should, in my opinion, be perfectly acceptable and in fact encouraged. I mean everyone else is blasting their's, so what's the harm? But let one line of Beyonce slip through your lips (or heaven forbid a small shimmy to go with it) and that one serious, puffing weight lifter who is too serious to need the distraction of music will give you the stink eye. Lighten up dude. You already look like Schwarzenegger circa 1980. Go home and eat some cake.