Preemption, Illinois, Zip Code 61276:

Just learned about this, thanks to commenter cathyf. If anyone knows the story behind it, please let me know. And please feel free to mention other similarly amusing names, though stay away from the obvious ones (this and this, plus the others linked to from here) unless you have something new to say about them.

Oh, and if you want to use Google directions to get to UCLA, don't ask for Westwood, CA.

UPDATE: According to Edward Callary, Place Names of Illinois, the name stems from "the preemption laws passed by the U.S. Congress that gave squatters the right to 'enter' (register) their land with the government and purchase it later when the tract became legally available for sale. The preemption laws protected settlers from claim jumpers and from having to bid against speculators at open auction." I found some 1800s court cases that confirm the existence of settler-protective "preemption laws," so this adds plausibility to the account. Thanks to commenter Alfred for the pointer.