After seeing a couple really cool examples of "four degrees of freedom" biped out there, I decided that I would make some cool feet and make the robots a bit more creature-like. Current ideas for cool feet are beasty feet, mech-like feet, rock feet.. you know.
The preceding examples of this type of robot used the pcb as the mounting point for the servos, and I've made a generic baseplate with room for a mini breadboard or your own preferred platform. I've also added a "neck" servo for looking around and ultrasonic sensor for sight. I plan to make a housing and more creature feet for this as there is much potential for customization.
The code I'm using is a derivation of the functions and primitives written for uBipedino (tm) by user Ro-Bot-X on the Let's Make Robots site. It is the part of the robot that is in progress, as I am working to fine tune the ultrasonics.
The link to Ro-bot-X's wonderful creation is here: http://letsmakerobots.com/node/30394
Arduped's home is at: www.handmadecircuits.com
Here is a video with some tips and tricks for assembly:
...and here is a video showing Aduped's first steps!
Print out the plastic pieces and bolt on the servos. I used foam tape to stick the feet on. I drilled out the holes on the servo horns a bit and used 2/56 x 5/16"L hardware to bolt everything on. For electronics I used an Arduino Nano, but there are many examples of PIC biped out on the nets too.