When I started college, I kept a hypertext journal with Storyspace. This pre-dated the Web by about three years. The journal was kept in one file, and many of us had our journals sitting in public places on the school's Appletalk network. Access to them was much more limited than on the Web, but it was still personal writing in public space.
I thought the entire idea of web journals was rather silly, until I started writing in one of my own. It reminds me a lot of what we were doing back in college with Storyspace, only with a much wider audience.
This strange activity seems linked in some way to Web cams. Personally, I think writing about what's going on and what you're thinking is a little more exhibitionist than putting Web cams in your house so people can watch you run around naked. I'm not sure if it's pathology or human nature to want to do this type of thing, but the Web has certainly made it quite common.
I only read a very small number of web journals. These are all written by people I have met, and they write well. There is humor mixed with the personal drama, and it *is* a way to connect with people.