The University of Minnesota researchers who run movielens (collaborative filtering for movies) have an interesting twist on tagging:
Dubbed "Tag Expression," this new approach to tagging will add more feeling to your tags. When you add a tag, you now have the option of specifying if the tag represents something that you like about the movie or something that you dislike about the movie.
Here's what it looks like:

You'll have to imagine the AJAXy drag and drop. Size here indicates tag frequency for that movie, and color indicates collective mood. The redder the tag, the more the users dislike that aspect of the movie; the bluer the better.
A ways back I thought there should be two kinds of tags -- "left-handed" tags that were subjective, and "right-handed" tags that were objective. (Yes, sort of like whuffie.) So, for example "Sean Connery" and "Science-Fiction" and "giant floating head" might be right-handed tags for Zardoz, while "fantastically bad" and "LSD substitute" would be a left-handed tag. But I think I like this method better, since it adds the dimension of feeling.
Incidentally, while tagging a movie I ran across one referring to the Bechdel Test for films, which goes as follows:
The strip popularized what is now known as the Bechdel test, also known as the Bechdel/Wallace test, the Bechdel rule, or Bechdel's law. Bechdel credits her friend Liz Wallace for the test, which appears in a 1985 strip entitled "The Rule", in which a character says that she only watches a movie if it satisfies the following requirements:
- It has to have at least two women in it,
- Who talk to each other,
- About something besides a man.
There is, of course, a blog dedicated to the test. Our regular readers will, of course, have already noted that Bechdel Test follows Stigler's law of eponymy.