pullups and pushups are pretty basic exercises.. but some of their variations are pretty interesting, but you cant base a whole workout around this. The main muscle worked in every single exercise ive seen is the tricep, and any other muscles worked are secondary.

point is all youll do is burn out your triceps without really working the rest of your body effectively.

if your seriously thinking about getting into shape then the best site is

www.bodybuilding.com

like willy said. if you cant afford a gym membership, check out the milk jug workout.

ps. sorry if i dragged down what was intended to be a light post. as everyone knows, bodybuilders like to preach and rant whenever they see an opportunity.