Earnie, I maintain two blogs, one public, one private. On the private one, I keep
a wealth of notes, images, etc. It's my go to spot for being able to find all the stuff I'm looking for (did I bookmark that article, e-mail it to myself, or see it somewhere online? Now I just copy the entire text and post it in my blog. I always know where to find stuff now. So much easier.)
Another person I know keeps a private blog for his investing notes. Every day, he highlights information he's read, etc.
Many chefs I know maintain flavor journals and notebooks with recipe ideas. Taking that kind of information online is also helpful. Again, even if it's private.
FYI - You can change your blog status to public or private. I'd recommend starting private, if that's the way you want to go, then making it public if you decide to go there. If you make it public and then switch to private, your previous content is still 'out there' on the web.