I'm on the sixth. I do all the content myself, my favorite is www.alop.org it's animal right project I started about 2 years ago.
Only one right now, and it's still a baby. But I already have an idea for a second. I figured I'd try to make one float first.
The question should be rephrased as " How many active blogs do you have?" Active being defined as having atleast 2 reasonably long posts in a week.