Turtle Wrench

This really does look brilliant.

An article on it with more pictures is at Yanko Design.

"You take this “Turtle Wrench,” right, and you attach it to your wheel: it connects to all of your wheel bolts at once. Now the wrench has four arms sticking out, one of them each a wrench that correlates with a bolt. You drive forward one full rotation, and as you push forward each wrench, it loosens a bolt."