One of the nifty things about using tags is that you can have automagically generated pages showing all the posts that have any combination of tags.
For instance, if I wanted to show all the posts which I’d tagged with “Weight” and “Exercise” and “Hairstyle”, I’d just have to put up a link like this one:
Or for all Doctor Who DVD posts:
Nice. I’m going to play with this some more…
 Not quite as many
 Not very many