Robo-Hominid is my first successful biped. He is a very compact stiff legged weight shifter. He can walk forwards, backwards and turn right and left under remote control.

He is has two motors, one for leaning, and the other for leg striding.

He uses homemade turntables built out of 2x3 L liftarms, 40 tooth gears and worm gears. This allows for leaning and leg striding in the same mechanism.

The left arm motor and a rotation sensor control the leaning by using a large pulley and a liftarm to shortening or lengthening the distance between the left arm and the left hip. 

The right arm motor and limit switches on the front of the legs control leg stride. As one leg goes forward, the other drives backards. As the motor turns, it goes through many gears and eventually drives two shafts that turn worm gears. The worm gears turn 40 tooth gears that turn the legs with respect to the body. When weight is applied to the leg, and the legs turn, the body turns with respect to the floor