Husband-and-wife combo Chris and Madeleine Ball have created a shirt that'll let you and the rest of the world know how much email you've got waiting for you when you're away from your computer.
It works by communicating with your computer via Bluetooth, with an Arduino Lilypad controller (powered by a AAA battery) on the shirt figuring out how many lights to turn on. You know exactly how many emails you have by adding up all the lights, so if you have two emails it will light up next to the two, and if you have three it will illuminate both one and two. If you happen to have 127 emails waiting for you, you'll see all of the lights on (and have a lot to do when you get back to your computer).
Check it out in the video above.