The PhantomX AX Hexapod is a pretty interesting robot for researchers and educators. It has 3 degree-of-freedom legs, Arduino-compatible robo-controller, and a totally hackable design. It also features wireless Xbee control via a PC or handheld device. As the below video shows, it is possible to control a PhantomX Hexapod robot using an iPhone/iPad.
As you can tell, it is also easy to control such a robot using a regular controller. You can find all the project files for OVPiPod on GitHub.[Source]