Some people love the extra efficiency of turbochargers, while some hate the uneven distribution of power that often accompanies the boost. Put it on a keychain, however, and you've got nothing but that beautiful, high-pitched hiss.
What makes these so awesome is that they're built kinda like a real turbo. There's an impeller that catches air from the air inlet, and spins up to 75,000 rpm. Most car engines self-destruct at less than a tenth that speed.
Check this video out, then try saying with a straight face that you don't want one of these on your keychain. Not gonna happen.