TweepyDeck is currently an experimental PyGtk client for Twitter.
To run it you'll just need to execute the tweepydeck script
% ./tweepydeck
I'm not particularly sold on using OAuth with Twitter, while it is convenient when you're working with web applications it's unpleasant (in my opinion) when building a desktop application.
Yes, TweepyDeck does prompt for your password but the application is using SSL for every API call that uses your password.
