After a few days of non-stop music, food, art and hot weather (not to mention all the sweaty and smelly people you're constantly bumping into), there's nothing more appealing then stripping off as many clothes as you're comfortable with shedding and jumping into the community fountain.
If you want to get away from the crowds of 80,000+ people for just a moment and see a great view of the festival grounds, the ferris wheel is the way to go. Bonnaroo 2008 was madness (the good kind)!
Burgess Falls State park in Tennessee. This is the biggest of the 3 waterfalls in this state park.