The Babel Fish
Aside from the Guide itself, this one was easily the first to come to mind for this article. Sure, we’ve got websites and phone apps that make traveling to places where you don’t speak the lingo much easier than in earlier eras, but that’s not nearly as cool as sticking a fish in your ear and gaining the ability to understand any language in the universe. In the Hitchhiker books, the sheer ridiculous usefulness of the Babel fish inadvertently solved a long-standing theological debate by both proving the existence of, and then negating the existence of, God himself. The Babelfish is an ingenious way to solve one of those problems that crops up a lot in science fiction: how the hell do all those different species talk to each other? There are plenty of similar ideas, ranging from Star Trek’s universal translators to Farscape’s translator microbes. None of them, however, are as entertaining an idea as the wonderful, ludicrous Babel fish.
The Guide says:
The Babel fish is small, yellow, leech-like, and probably the oddest thing in the Universe. It feeds on brainwave energy received not from its own carrier, but from those around it. It absorbs all unconscious mental frequencies from this brainwave energy to nourish itself with. It then excretes into the mind of its carrier a telepathic matrix formed by combining the conscious thought frequencies with nerve signals picked up from the speech centres of the brain which has supplied them. The practical upshot of all this is that if you stick a Babel fish in your ear you can instantly understand anything said to you in any form of language. The speech patterns you actually hear decode the brainwave matrix which has been fed into your mind by your Babel fish.