The zipit z2 is a hand held linux device. It's meant to be an instant messaging client targeted at teens. Fairly nifty device in and of itself, but the fact that it's an hackable ARM device that runs linux is what makes it most valuable to me. I use mine as a palmtop linux system.
ebindkeys for Zipit is a port of a daemon I wrote for linux. It reads in input event data from /dev/input/eventX and executes commands based on a config file. For example, you can bind the “options” button to step through brightness levels.