Gun free schoolzones
Alan Korwin has an interesting map depicting effect of the "Gun Free Schoolzones Act" in reality. Here's what its ban of guns within 1000 ft of a school looks like in Phoenix. I've seen depictions of Tucson, with similar results.
The one good thing is that no cases have been brought under it, for the simple reason that it's unconstitutional. The Supremes struck it in Lopez, for lack of a connection to interstate commerce. So Congress re-enacted it with a list of findings that possession in such areas does affect commerce -- but the opinion had noted that such findings would not affect its unconstitutionality. Glad to know Congress takes such a serious attitude toward its oath to support and defend the Constitution.