Here's another one from last night: Don't put your face on the drinking fountain. The reason it shoots the water up is so you can get the water without touching the fountain itself and exchanging cooties with other people. I was just about to get a drink last night, and the guy in front of me puts his mouth in contact with the metal guard piece, so I had to go and use another fountain. Now I'm not a super-germaphobe, but this should be common sense.
Oh, yeah, and quit leaving your gum in the drinking fountain or the urinal.