TuneTweeter
TuneTweeter is software that posts your current iTunes song to your Twitter page. The app will monitor iTunes and, whenever the song iTunes is playing changes, it will post some information about that song to the user’s Twitter account. This software is in beta and can be downloaded from here. Give feedback to @tunetweeter on Twitter.
Note: Make sure you have iTunes running before you open TuneTweeter. Otherwise TuneTweeter will crash.
Filed under Apps, Mobile, Silverlight/WPF, Windows Desktop |Twitterlight
Twitterlight is a Twitter client built with Silverlight which provides features like auto-update and TinyURL support. The Twitterlight code is available here as is the explanation as to how it all works so you can build your own Silverlight Twitter client, too. (Read more).
Witty
Alan Le of Vertigo designed a WPF Twitter client called Witty to bring Twitter onto the Windows Vista desktop using the Windows Presentation Foundation built into Vista and the Twitter API. Like any desktop client, you can receive updates from your friends and update your status, too. The app can also dock into the system tray. You can download Witty from here.