Twidge is a command-line microblogging client for Twitter and Identi.ca. It is designed to be useful when you're sitting at a shell prompt.
While I prefer TTYtter, Twidge may be easier to use and also can be install with just one command.
Using a command line Twitter client can be very useful because you can use the power of a shell to tweak everything you need. For instance, you can scheduling future updates (with at), ignore certain updates (with grep), etc.
To install Twidge in Ubuntu, open a terminal and paste this: