well, i think the one i'm proudest of would have been from a nacho cheese pump i took when i worked at taco bell... granted i didn't really "make" it so much as i just took the pump and the spout off and used the tubing! there was a hole in the bottom where a bearing goes that allows the cheese to get pumped, but i took it out and used the hole as a carb. after a month people started noticing that one of the cheese pumps were missing :clap: