Scott McNulty noted Tweet in his Twitter feed as well as on TUAW. I downloaded Ted Leung's Growl-modified version of Coda Hale's script. Coda has good installation and usage instructions in the original Tweet script, which you can use if you don't care about Growl support. Tweet combines the power of AppleScript with that of Quicksilver (you are using Quicksilver, aren't you?) to make posting to your Twitter account easier and faster than ever. Sorry, Windows users, but all of this, except the Twitter service itself, is Mac-only.