The following project shows how to create a tele-presence robot using stuff like the Arduino, Pololu WIxel, iPhone with Facetime and a sparkfun magician robot chassis.
The motors used in the project is controlled by a serial connection to the Arduino transmitted over the Pololu Wixel wireless device. The Wixels are small devices that help in providing a wireless connection that is somewhat similar to the USB cable. In addition to the motor controls, the arduino can also be reprogrammed so that it is more user friendly.
Apart from this, the Wixels have many more capabilities and can easily handle all of the processing requirements of the project directly without the Arduino by using a custom program, but the wiring is muchmore simpler while using it in this manner.
One can also double-stack the Wixel and Motor shields by using a couple of extra pin blocks. Instead of using the Pololu devices, the Xbee can also be used in the case, but the main reason for using the Pololu devices is that they are much cheaper. Moreover the extra mesh networking capabilities or range of the Xbee is not required here.