If you're not sure what P90x is, check out the P90x website. It looks hokey but it's actually a really well thought out full body workout. A lot of it is just body weight and resistance bands, although you can use weights.
So far we have the following people:
A tentative date for starting it was thrown out by Mike JacobX as December 7th. Both Jacobs and I have set of the P90x DVDs.