The ElecFreaks.com Joystick shield can be combined with a nRF24L01+ wireless transceiver.
If the Zumo Robot is extended with such an nRF24L01+ transceiver module, the Zumo bot is controllable with a joystick. Great fun to drive the robot with a joystick around. The nRF24L01+ transceiver is sensitive to voltage drops, and this article explains the problems and as well the solution:
mcuoneclipse.com/2014/05/16/joys … umo-robot/