The Digital Streets blog posts a tip on how to send Twitters from a command line using a little utility named cURL. The blog shows the command to install cURL in Ubuntu, but the app is available for Linux, Unix and OS X, and Windows as well. Once you're set up, the terminal terminology is:
curl -u yourusername:yourpassword -d status="Your Message Here" http://twitter.com/statuses/update.xml
You could save yourself a bit of time by putting most of that text into your preferred text replacement app, or setting up a terminal shortcut. Either way, it could be a convenient way to get at some of Twitter's more useful features, like setting GCal events, Remember the Milk, or just setting plain ol' SMS reminders. Got an easy way to set this up in your own OS? Share your experience in the comments.