Body weight can incorporate your entire body.

Look into Convict Conditioning, Beast Skills, etc if you are interested.

i'm also interested in exercise that uses your own body.
what are some good ones?
push-ups sit-ups
leg lifts pullups lunges
these are what I usually do

>>11010
Burpees, bodyweight squats.

Also, go ham and try out different ways of pushups:
http://artofmanliness.com/2009/07/21/push-ups-exercises/

Crunches and bicycle crunches are some variations on situps. That way you can hit your upper abs and obliques more. Someone told me situps have some unnecessary movements in it that make it less effective than crunches. Not sure about that.

Dragon flags for lower abs

Get into a Gravitron. When at full speed, do some sit-ups. Roll around, and do some push-ups. Then stand up, and proceed to do a few squats, arms outstretched in front of you. That should do.

>>11010
Pistol squats.

Hand stands, for support muscles and balance.

Hand stand pushups if you can do them.

Yoga leg lifts. (Lifting legs and lower body while supporting with upper back and lower arms)

Horse stance/ wall sitting(?). Add light weights held in hands as you advance. (like, water bottles or whatever)

Karate-water-jar style lifting for fingers/lower arms. Technically not bodyweight but adding it since you can do it with random items from home.