I was playing with google seeing what keywords would return my blog, and I saw Chris Muir mention my presentation on his Twitter feed.
Now I have chosen not to fall into the Twitter trap, but there are some feeds I wouldn't mind following, Chris being one of them (Doctor Karl being another!)
For those uninitiated into RSS aggregators such as Google Reader, you can subscribe to these Twitterers & read what they have to say without needing to sign up to Twitter.
Kinda like reading all their mail, I guess... I can't tell you if there is some sort of privacy option within Twitter that controls this, perhaps someone with an account can?
I recently subscribed to one that had what I thought was a sensational idea - As part of the 40th anniversary, NASA arranged a Twitter feed for the moon landing, so you could read what was going on as if it was happening real time today. It gave a wonderful sense of time and progression for those of us not around when it happened.
I think it's nifty.