I've used mine as a personal knowledge base that happens to be public. It's silly how many times I've come up in search results months or years later after I'd forgotten having solved this problem before.

A semi-related story: Freshmen year in college, I was about a week ahead in the sci curriculum and I blogged regularly about novel errors I encountered and how I fixed them. During lab late in the semester, I happen to look up into the next row. I found the duo there reading my blog post.