From Phillist, a guide to polite behavior at concerts, spurred by numerous summer festivals.

Excerpts:

Footwear
“If you’re wearing flip-flops and the need to surf hits you, take them off and hand them to a non-surfing friend before you go. Few things are ruder than dropping your shoe on someone’s head.”

Personal Space
“If there are girls in the [mosh] pit (sometimes, there are), do not, repeat DO NOT use the pit as an opportunity to feel them up.”

Projectiles
“Keep in mind that you’re there to enjoy the concert, and other people are there to enjoy the concert, and you don’t want to be the asshole who ruins it for everybody by seriously injuring someone in the crowd, or, worse yet, one of the security people. Instead, try opting for (as many people did) inflated condoms (unlubricated, please!), available for free in their uninflated form at the Trojan tent.”

Good points, all. Follow the link to read more.