I started a personal LJ in 2001 and kept it going for over 2 years. I was sad when i had to lay it to rest. In some ways, it was a relief, an opportunity for self-exploration. In other ways, it exposed me, made me vulnerable in ways that i wasn't prepared to handle in this format. I took it down.
Eventually, my research blog started getting infused with personal notes. It's now kind of a blend of my LJ and my research blog, but not really the same.
If you're curious, you can read it here