Bablefish
The Babelfish is small, yellow, leachlike and probably the oddest thing in the universe. If feeds off brainwave energy, absorbing all unconsious frequencies and excreting, telepathicly, a matrix picked up by the speech centres of the brain. A practical upshot of which is that f you put one in your ear, you can instantly understand anything said to you in any form of language. It is so bizzarely inprobable that something so mind bogglingly useful could evolve naturally that some thinkers have decided to use it as the final clintching proof of the non-existance of god. The arguement goes something like this:God: I refuse to prove that I exist, for proof denies faith, and without faith i'm nothing.
Man: Ahh, but the babelfish is a dead givaway isn't it? It proves you exist aand so therefore you don't.
God: Oh, I haden't thought of that...
...and promptly vanishes into a puff of logic.
Most leading theologans believe that this is infact a load of dingos kidneys and the theory was dismissed. However this didn't stop Oolon Kahloofid Making a small fortune when he used it as the central theme of his best selling book: "Well that about wraps it up for god."