Watch this! It's a gem!
Just watched the movie and I can advice anyone else to do so. The plot is brilliant and keeps you guessing all the time, til the bitter end...
Okay, the ending (don't worry, I will not spoil it here!) has been done before and thus is not completely original, but I never saw it coming anyway.
Now I'm just wondering how long it will be til Hollywood picks it up for a crappy remake...