I know this is out of our area, but if anyone goes to Indianapolis check out
http://www.ftik.com/
Best Karting I've ever experienced, and if you go the night before Indy500 you can watch the drivers have at it.
http://www.youtube.com/watch?v=xKwJdMUg5Zc (Dude doesn't seem to push it very hard. But you can get a feel for the layout.)