Internal blogs are a good idea, but I'd never set it up on the Internet-- even with a password.
Seth Godin suggests that it's a perfect time for people to start an internal blog. The idea being that it is like a daily diary, so you can look back at how you dealt with day to day issues. I think it's a good idea, but since many of the issues I seem to deal with are the personality quirks and technological ignorance of my "clients", I can see this diary becoming a nightmare if it became public somehow (e.g. FOIA request, legal action, successful hacker incursion, etc.)
If you decide to take Seth up on his advice, you might want to consider using Wiki on a Stick instead. Go on, you've been wondering what to do with that cheap, promotional 128 MB USB thumbdrive you got from that conference/demo/Halloween party, anyway.