Here's an interesting one: the tattoo artist who did Mike Tyson's distinctive facial tattoo "has sued Warner Bros. over the similar-looking facial art on Ed Helms' character in the upcoming comedy 'The Hangover: Part II.'"
Lawprofs Kal Raustiala and Chris Sprigman discuss the case over at the Freakonomics blog. They point out, first, that as "works of graphic art," tattoos are subject to copyright, and add that, as attached to Tyson himself, there is probably an "'implied license' between Tyson and [tattoo artist] Whitmill that Tyson will appear on camera now and again, and therefore so would the tattoo." But the problem here is that, in the new movie (as opposed to the first Hangover), the tattoo appears on Ed Helms's face (not Tyson's). The "bottom line," they say, "is that Whitmill’s claim is not frivolous, and he may well get a big payday from the studio just to make him go away."
UPDATE: George Wallace gets off a good line.