The Vans Warped Tour is traditionally a festival of punk rock and ska music. It's kind of like a "cool" lollapalooza, with more than 20 punk/ska bands playing throughout the day. Since it's put on by Vans shoe company, there is usually a lot of skateboarder types there (halfpipes, etc.)

It travels around the U.S. during the summer and is well worth the 20 something bucks it costs to see it.