That's My Mug

Oh no, I left my plug in my other pants!

Great idea for people who want to keep their coffee (or wine) mug to themselves and not have to deal with people using your office mug for there own liquids.

The way it works is you can remove the plug and walk away leaving a nice whole in the side of the mug. The only way around this would be if someone bought a duplicate mug and only took the plug-key to work. But who would work in an office with stuff like that going on...