Here is the walking quadruped robot that I made some time ago –
It turned out that 4 legged motion is pretty hard to get right. It took me 2 weeks to fix all the balancing and motion issues, so it can walk well. Turning left and right was especially challenging since it does not have enough levels of freedom in some directions. It uses 12 servos, but still can work pretty long time. It seems like Bioloid servos are pretty efficient. Makes lots of noise when walking though. Biolod coding language also does not scale well when you try to implement complex logic. I guess the best approach is to control the robot from a PC (or netbook) and use onboard controller only for low level motion control since it is pretty limited.