I think it was last year when Taco showed us Pandora.com for music. There is a website called Criticker.com that allows you to rate movies from 0-100 and gives you matches on movies that it thinks you will like. And it is amazingly close.
The websites Probable Score Indicator(PSI) gives you a score, that score is based on how you have ranked previous movies. The more movies I've ranked, the closer the PSI gets to my actual ranking.
The site will also give you something called a Taste Compatibility Index (TCI). TCI's are people who have ranked movies similarly to what you have ranked movies.
The website is handy when trying to pick out a movie from the theater or something to rent. But one thing that I'm enjoying about it, is the ability to pick up movies from several years ago that I may have never heard of or forgot about and always wanted to see.
here is my profile