Tags!
I just converted all my categories to tags. Categories are supposed to be used in a sparing manner, and since WordPress.com never had tags until last week, I was using the categories as tags. Which resulted in me having thousands of categories. So, I’ve used the new tool released by the fine folks at WordPress.com to convert everything to tags, and I’ll be starting my categories system for broad categorization (of course) and using tags to generate specific filing marks for each post from here on out.