Digsby(but still use for msn and yahoo) for it. The first wow factor is it's the interface. Its looks so beautiful and well managed. Making groups for seperate stuffs on facebook looks great and is easy to see whats happening.
It is a free application that lets you connect with your Twitter, Facebook, MySpace and LinkedIn Accounts. It is supported by Adobe Air(no wonder how the interface looks) so you will need to install Adobe Air first to your computer which is not a problem because it is automatically downloaded when installing the app.
You can update your status, comment on others, like other comments, upload picture, share links and do almost anything you do on your regular browser based facebook. Try it, you will love it.
Download it from http://www.tweetdeck.co.
Also want to know how twitter goes with it? Click here