NortHACKton member, Charlie Webb, recently completed this project based around an arduino and a keyboard. Fed up with the way Windows forced him to switch between his different keyboard layouts (qwerty to Dvorak) he decided to take the process entirely out of windows hands. He modified an old keyboard, inserting an avr microcontroller between the keyboard and the PC. At the flick of a switch the MCU performs the entire keyboard remapping between the two different layouts.
The microcontroller in the keyboard also allowed him to add some extra features at the same time. The big red button on the front of the keyboard generates a whole stream of text to be inserted into whatever you’re working on. Knowing Charlie I suspect this is currently being put to extremely good use harassing the noobs on some First Person Shooter somewhere (“OMG, WTF, I Iz Leet” etc, or maybe minecraft as that’s what the cool kids seem to be doing atm)
More photos and some diagrams of the project can be found in on picasa
And he has been kind enough to supply us with the arduino code for the job too.