Sparkfun Joystick Shield w/ XBee and Powercell
Small, portable Joystick for sending XBee commands to robots.
I use a Sparkfun Joystick Shield, an XBee Shield, a LiPower Shield, and an Arduino UNO for a easy controller for things like robots. Its a great way to get a joystick and 5 buttons for controlling whatever you need. It's really nice, but three shields plus the Uno itself makes quite a large arduino sandwich! It's a regular leaning tower of shields.
This project is my plan for making a much sleeker, standalone controller that will be much smaller. Small enough that I can make a cool 3d printed case, perchance!