One thing learned last year was this: Bring your sunglasses! The stage faces east, and the setting sun is pretty freakin' bright over the heads of the singers. If you think you'll be OK by just turn-ing around and listening to the music, you're kidding yourself. The reflection off Gateway One is bright enough for Lasik surgery. Also, it's going to be hot. Once the sun goes down, it's going to be hot and dark. If it rains, it's going to be hot and humid, with a 100 percent chance of your undies' creeping steadily northward.
Bring a blanket to sit on, but remember coolers and glass containers are not allowed. You can also bring canned goods and other nonperishable items for a food drive benefiting Food Outreach, an organization serving folks with HIV and AIDS.