IDENTITY (2003)
I saw this years ago, and recently bought a copy (Wiki review contains spoilers.) Excellent "Everything-is-not-what-it-seems" thriller.
http://en.wikipedia.org/wiki/Identity_(film)
http://www.youtube.com/watch?v=tIfcdg7etE0
I really like this movie. It's one of those ones that I can watch over even though I know how it already ends.