Different Physics for Different Bodies

Sorry if I have just missed it some place in the forums, sample codes, or the other resources.

Is there a way to set certain physics to just one body. For example if you wanted one object to have anti gravity and another to have normal gravity. ( If that makes sense.
I appreciate any help.
-taco [import]uid: 28130 topic_id: 5688 reply_id: 305688[/import]