Here is a collection of various bodyweight exercises that should work the body without the need to do hundreds of reps per exercise. I've tried to give most a short explanation but if something is not understood, please post and I'll try to give a better explanation
Light Exercises:
Upper-body Push:
Inclined Pushups
Triceps Pushups (hands close, underneath face)
Upper-body Pull:
Hanging Rows (lie on your back, grab a hold of a table or something of similar height and do pullups while keeping your heels on the ground)
Legs:
Lunges (both taking the step forwards or backwards)
Split Squat
Abs:
Crunches
Medium Exercises:
Upper-body Push:
One Arm Pushups
Handstand Pushups
Bar/Table Dips (like normal dips but you need to lean forward more)
Upper-body Pull:
Pullups (if there is something to hang from, personally I do them hanging from a door)
Legs:
One Legged Deadlifts
Wall Squat (with your back against the wall, keep the lowest part of a squat for as long as you can)
Abs:
L-Seat
Hanging Leg Raises
Hard Exercises:
Upper-body Push:
Tuck Pushups
Upper-body Pull:
Uneven Pullups (like normal pullups but instead of pulling straight up
One Arm Pullups (if your a freak

)
Legs:
Pistol Squats
One Legged Wall Squats
Abs:
Prone Pike (like that abdominal wheel they have on tv-shop, but instead of a wheel in your hand keep a folded up towel underneath your feet and pull your feet towards your hands)
Total Body:
MuscleUps (kind of like a pullup continued over the bar to a dip)
Reverse Plank (lie down on your back with your head towards a table or high stool. Put your palms on top of the table/stool. Push down with your hands and heels so that you lift your body from the ground, like doing the reverse of the abdominal wheel)
Some links:
http://www.beastskills.com
http://www.dragondoor.com/articler/mode2/Workouts