Have you got any stairs? Is there a place you can put a pullup bar? Do you have furniture you don't care about?
You could spend some time training your jumps. I also second the gymnastic bodyweight exercises. Do a lot of quadrupedal work, even mocking a jam in this way (vaults, tic-tacs with your hand posted on the floor, etc.).
Or check out this video:
http://www.americanparkour.com/content/view/4160/431/Other thread that might help:
http://www.americanparkour.com/smf/index.php/topic,23152.msg282775.html#msg282775You've got to learn to look at things differently. Instead of going around the dinner table, go under it. Hop across the house instead of walking. Do a vault to sit on the couch. Kong onto the sink and crouch there while brushing your teeth. Heck, crouch on the toilet while doing your business (which will turn out to be useful if you ever visit China, believe you me). If you have a balcony, climb it/vault it. Tictacs off the walls, vaults over the arms of the couch or chair. If you own the stuff, there's no end to the possibilities. If you're under your parents' care or rent or share...beware.