Tags have become a big part of WordPress. Back in the day we had categories and that’s it. A user could search the site for keywords, but categorizing a post couldn’t be accomplished without a ton of categories. Recently I added a bunch of categories, reassigned my posts into them and ended up with a lot of categories with only a few posts in them. I had been resisting the movement towards tagging and wanted to hold onto my categories. In WP 2.5 tags have been integrated into the core and it is clear there is a role for tagging.
The main issue I was having with categories is that I was using them to say what a post is about. For example, if I had a post about our wedding, it went in the Wedding category. But once our wedding was over I had like 10 posts sitting in a category that would never be added to. With tags I can place those posts into “Life Stuff” and tag it with wedding. The category becomes a general bucket and the tags describe exactly what the post is about.
I’ve made some theme changes and added a list of tags on each post. I went back through all my posts, recategorized them into my core categories and added tags. Now I have 8 categories and over 100 tags which will be much easier to manage and will keep me from trying to stuff my posts into overly specific categories.