This would be a good start: http://generichid.sourceforge.net/index.html http://generichid.sourceforge.net/index.html A toolkit for making your own USB human i

This would be a good start: http://generichid.sourceforge.net/index.html http://generichid.sourceforge.net/index.html A toolkit for making your own USB human interface devices. Supports a variety of chipsets, including the AVR variants in the parent comment. Comes with its own crazy visual drag and drop programming language. Get involved! EDIT: Aha! found the link I was looking for: "Program Your Own Mayhem-Causing USB Dongle" http://hackaday.com/2010/04/05/program-your-own-mayhem-causing-usb-dongle/ http://hackaday.com/2010/04/05/program-your-own-mayhem-causi... It's a video presentation BTW. And it is seriously devious: "There’s also a light sensor that can be used to activate a command once an unknowing victim has shut off the lights in the office and left for the day." EDIT2: For bonus evil-points, solder it into a USB hub, run a real HID into the same hub, and hide the whole thing inside the HID, with the hub's host port wired up to the cable of the HID. Read the link below to see what I mean. http://www.thice.nl/hide-your-data-in-plain-sight-usb-hardware-hiding/ http://www.thice.nl/hide-your-data-in-plain-sight-usb-hardwa...