Digsby
digsby is a multiprotocol IM client that lets you chat with all your friends on AIM, MSN, Yahoo, ICQ, Google Talk, and Jabber with one simple to manage buddy list. Other than that, it also serve as email notification to your Hotmail, Gmail, Yahoo Mail, AOL/AIM Mail, IMAP, and POP accounts.
I’ve tried my msn account, email account and facebook account. All working.
on 
FoxTwo
August 19, 2008 | 11:48 PMI have actually written up on Digsby too, and that was before it even had Facebook chat support.
With Facebook chat support, you can chat with your friends who are in Facebook, without you needing to be on Facebook!