Here's a fascinating look at the most misquoted lines that have crept into our language incorrectly from film. And, yet, many are are now a standard part of our phraseology in their altered form. And there's audio clips for reference.

Some are as old as Cagney's "You dirt rat!' and Gary Cooper's "Smile when you say that"; others as recent as Star Trek's "Beam me up, Scotty" nad Star War's "May the force be with you":

http://www.filmsite.org/moments0.html