Everybody has a lug wrench in their car. Well, most do. If you don't have one, time to get to the parts store, it's a necessity. Just ask this guy.

Hey, when you need a lug wrench, you need a lug wrench. If your car's out of commission, you can always ride a bike to the auto parts store for a proper wrench. Bike chain broken? You can skate there. Live in a country whose balance of trade is a one-way door leading out? You can always make one with an old socket and a piece of steel rebar.
This tool may not be useless, but the amount of time it took to make it from scratch really calls into question the usefullness of the guy who made the decision in the first place.