...Where you get your info from? "That's what gymnasts use."
Dude, think about it, gymnasts don't weightlift! They use bodyweight conditioning and calisthenics, duh.. that's common sense.
Tutorials
Building an Olympic Body through Bodyweight Conditioning: A Bodyweight Strength Training article from Dragon Door Publications
FightingArts.com Forums: Exercises without weights
These are good.. only if you REALLY think you need it, because you generally don't.