A real easy project, cut off one end of a guitar cable, attach it to the contacts on the ear piece (make sure the two sides don't touch), talk into that shit. I moved the speaker down into the normal talking area, and it doesn't sit very well, but it creates a cooler visual, I think. (Sorry I effed up your phone, Jake).
From the inside of a stuffed SpongeBob Squarepants, he had a button in his nose and arm which made him speak. Hitting the button mid-sentence shuts him up with a cool squelch. Pressing both with rapid-fire results in wacky sounds and manic gibberish.
I put too much stuff in this and it won't close, but now I can just press on the casing to change the speed because it actually puts pressure on the motor. The contacts on the side add some extra crackling when touched, and can stop it entirely when connected with wire.