Anything called the Annoy-a-Tron is worth a mention here
Bug your friends, family, and co-workers.
Just think. You can hide this slim, inconspicuous device from ThinkGeek somewhere in one of your co-workers' cubes, and unbeknownst to them, it starts making annoying noises. Sure, they're hardly noticeable at first, but after a few hours of regular beeps--every 2 to 8 minutes, depending on how you configure it--this thing will drive your colleagues absolutely nuts. And the Annoy-a-Tron's teensy size will make it really difficult for them to figure out where it is. What a great idea!
ThinkGeek provides a list of guidelines for Annoy-a-Tron use, including the fact that you probably shouldn't hide it in food. I propose an addition: you really should only use it to annoy humans. Yes, your neighbor's irritating cat might deserve a prank or two, but this little device could mean bad news if you use it to tick off domestic animals. Or wild ones, for that matter.