There of course is this problem of why would I give my $$$ device such a treatment.

Anyway the project I currently play with involves creating new firmware for the http://www.saleae.com/logic/ analyzer. It must be possible to hook it up to the nXXX to create one of the following:
-A simple quiz game where everybody has a button they can press buttons
-Some radical input device (gloves?)

But what really give me a warm feeling is the a application like http://elisator.garage.maemo.org/ that would require hardware.