I've been using this to help me stop snacking late at night. If it try to raid the fridge at a certian time, a pressure resistor on the fridge triggers and arduino which posts to my Facebook wall and Twitter feed, via WiShield and PHP, that I'm trying about to raid the fridge so my friends can give me a hard time about it.
Just put out an instructable for the simple version of it, http://www.instructables.com/id/Gut-Check-Fridge-a-Tweeting-and-Facebooking-Fri/
And a small tumblr site to explain it a bit better, http://cyancdesigngutcheck.tumblr.com/