What myth can you bust?

The Discovery Channel's Mythbusters show features a group of Hollywood effects experts who examine common myths scientifically to determine if they're not true (busted), could possibly be true under the right circumstances (plausible), or are true (confirmed).  Chances are there's a commonly-held myth you know about and can bust.  Why not blog about the myth and explain how you have busted, or could bust, the myth.