When people ask me about a movie I say two things: whether it was good or bad; and whether it was better than X or worse than Y where X and Y are two movies that are similar to it.
I never say FOUR STARS! Or NO STARS! That's just silly and not helpful to anyone.
I stumbled onto Netflix's contest last week while re-organizing my queue and I've been tossing ideas around in my head about how to solve it while I sit on the train. I couldn't come up with an interesting algorithm, so I took the cheap way out and decided their data is bad.
I'd prefer to track my movies based on their relationship to other similar movies (if possible) and then I would like to browse movies based on the same data my friends supply.