Dave, if you get the right conditions it allows you to ridiculous things, things that you can't do on pavement or dirt, power slide on either side and not worry about your leg or the bike, fall off deliberately to see what it's like at various points of the fall with out hurting yourself, up right 360's, under power with out having to worry about killing yourself. It makes you a better rider in normal conditions because your body remembers some of the process and compensates for the problem. It's also a huge blast. Sand would be good too except you've got clean sand out of your bike and you.
Bill the demon.