Dave Winer's Twittergrams are an interesting novelty that still needs some work in my opinion. He's getting some ink on it though, both pro and con. I've been playing around with the novelty and having some fun.
The essence is you call in a short message to your Twitter account and it's posted on Twitter. The difficulty is that you have no idea what the TwitterGrams contains until you listen to it. Which could be the point, but to be useful I'm thinking some folks need to see what the subject matter may be. Still, it could prove to be an interesting step in the whole presence thing.