Jamie Matthews created a nifty notification cube that glows when his Gmail inbox has a message.
I was given a lovely glowing cube by the generous people at Linden Labs as a freebie at a job fair yesterday, and I decided that it was far too attractive to simply sit there on a shelf, pulsating forlornly until its batteries went flat. How about making it useful, while maintaining its visual appeal?
A simple python script runs on his computer, periodically screen-scraping his Gmail inbox looking for new mail. It then outputs a message to the serial port, indicating the mailbox status. On the other end of the serial connection is a Boarduino, which receives the message and toggles power to the cube.
You could start with his code and get a jump-start on doing something similar. It looks like this could inspire a fun project or two on a lazy afternoon.