Humanoid bipedial locomotion (aka walking and running) is very hard to replicate. I suggest a few things:1. Do what roboteen suggested. Look at mother nature's notes and cheat the **** out of it. Or you could copy off of someone who copied nature... You are bound to run into problems with balancing and transversing rough terrain (eg, your messy room). There are ways to do it easily, but they are **** slow and still have problems.2. Use 4 or more legs. 4 legs is more stable than 2. 3 tend to tip over when moving.3. Best idea: Use wheels or treads. Its much easier, and you can get most of your supplies easily (RC stores are good for small wheels) No balancing is needed (unless you are building a Segway bot... Which in your case is a possibility). Also, programing a wheeled/treaded robot is much easier.