Google's special logo for August 12, 2010 reminds us that it's the 71st anniversary of the release of The Wizard of Oz, which, though we now think of it as a classic film, wasn't all that highly regarded until it became a TV staple during the late 1950s.
An urban legend of more recent origin (possibly coinciding with the 50th anniversary video release in 1989) holds that unbeknownst to the director, cast, and crew, one of the actors who played a munchkin in the film committed suicide while the camera was rolling and for some reason the shot was never edited out. It can still be seen to this day (including in YouTube clips, some of which contain helpful blow-ups).
Here's an example of the factoid as posted on the Internet in 1993:
A co-worker told me today that there is a scene in the Wizard of Oz where you can see one of the midgets hanging from a rope in the background. She said set conditions were so bad, and all the midgets were treated really badly, and one decided to hang himself on a prop tree.
Amazingly, it's still in circulation despite having been debunked ad infinitum (by munchkin confidante Paula Poundstone, among others). As many have pointed out (and as can be clearly enough seen even in the fuzzy video clips), the dimly-lit figure moving around in the background of the scene is actually one of the live exotic birds distributed around the set for visual interest.
• The Wizard of Oz - About.com Classic Movies