To categorize or not to categorize?

That is the question.
I have wondered, of late, if I should continue to bother. If I shouldn’t just stop categorizing, and kill all current categories. As a blogger, some times it is downright annoying trying to categorize a post. If a category doesn’t yet exist, you have to create one. If you create one, then you may go months without a post assigned to that category again.
I have found, as a blog reader, that I really don’t pay attention to categories on others’ sites. If I discover a new blog, and want to read more than just the post that brought me there, I usually go in reverse chronological order, rather than sorting through categories.
I know some of my fellow bloggers out there utilize categories, and some do not. I’m looking for both bloggers and blog readers to weigh in on this issue. Leave your thoughts, pro or con (or both), in the comments.