I almost ended up using Comcast's "Comcast Cares" Twitter account the other day due to a billing mistake.

http://twitter.com/comcastcares?sess=7fd22e18b74852a62dc6659...

As annoyed as I am with my frequent service outages and the billing error, I really like the notion that I can complain publicly and have their response (or lack thereof) also be made public.