You can download the tool here
Twitter-Sync is a new plug-in from WackyB that lets you keep Twittering away when using your favorite Instant Messenger 
It’s main features are: 
* Keeps your Messenger status and Twitter in synchronization with each other
* Changing your Yahoo! Messenger status updates your Twitter automatically!
* Update your Yahoo! Messenger status from anywhere in the world! Messenger status automatically updates to show your latest Twitter!
* See your friends latest Twitters right in your messenger window…
* Expanded window shows the last 10 Tweets from you and your friends
* Alerts and notifications for new Tweets received
* Twitter-Sync will NOT update your status if you are currently Invisible
* Lots of options to configure Twitter-Sync how you want!
