Didn't see a better place to put this, but I got bored a couple weeks ago, and took the vibrator motor out of a dead cell phone, and soldered it up to the connector from a dead carto, then slide a clearomizer tube over it, and put the end plug back in, with some tape to hold the motor in the tube, and hot glue to stabilize all the wires. Basically, you put it on your battery, and wait for a chance to offer it to someone, they put it in their mouth, hit the button, and promptly freak out when the unit starts vibrating...

