According to the Huffington Post,
"In the realm of legend, Marisa Tomei's 1993 win for Best Supporting Actress in "My Cousin Vinny" was long rumored to be a mistake, due to presenter Jack Palance calling out the wrong name rather than "real" winner Vanessa Redgrave. The Academy has long insisted that Tomei was the genuine winner."
Snopes.com calls this rumor false. Although, it doesn't sound impossible.
Click here to see the list of winners from last nights 81st Academy Awards. Proud to see Sean Penn, Kate Winslet and Heath Ledger win.