The current voting stats for The Avengers
movie once again make me think that there ought to be something in place to discourage IMDB voters from rating something as ten or zero.
Perhaps a message that appears when they select 10:
"Are you sure this is better than any movie that has ever been released? You may well be enthusiastic about it, probably because you've just watched it and it has blown your mind, but perhaps you ought to watch some of the top ten movies first."
And a similar-ish message if someone votes zero, with appropriate opposites mentioned. "This movie may well really S***, but there are sucky movies, then there are the ones that are in the bottom 100 of IMDB. Perhaps you should watch some of those first before (probably) going overboard when rating this movie."
Or perhaps just flat-out rejecting a rating of 10/0 if someone hasn't written any IMDB reviews before.