Thanks to the assistance of Philip Lindsay who created the UsbKeyboard library for Arduino I got a USB shield working tonight that allows an Arduino to pretend to be a HID (Human Interface Device) such as a keyboard or mouse:
This opens up a bunch of very intriguing possibilities, such as having an Arduino provide keyboard input to desktop applications including games. Andy Gelme is doing a talk at Linux Users Victoria next week about taking over the world with Arduino and wearable computing, and we’re hatching a plot to use our bodies as physical input devices to control a game through the USB shield above. Should be fun!