I was looking for an easy way to build custom chassis for various robotic projects. So, I purchased recently the LEGO MINDSTORMS NXT kit. I think that the NXT is an easy way for experiments or prototyping.
I started with the quick project suggested by LEGO in order to learn the shapes and combinations of the various pieces.
After a few days I decided to make my first NXT robot; the NXT Cicala (a two wheeled balancing robot).
I used the light sensor in order to measure the slope of the robot as in the original Cicala version. I wrote a little program in NXC (a simple PID controller - manually adjusted for my sensor and motors) and voila.