twhirl is a social software desktop client, based on the Adobe AIR platform.

Some of twhirl’s features:

    - runs on both Windows (2000/XP/Vista/Win7) and Mac OSX
    - connects to multiple Twitter, laconi.ca, Friendfeed and Seesmic Video accounts
    - displays notifications for new messages
    - shorten long URLs (using digg.com, bit.ly, snurl, twurl or is.gd)
    - cross-post your updates to Jaiku and many other sites like Facebook, MySpace, LinkedIn and more via Ping.fm
    - post images to yfrog
    - search tweets using Twitter Search and TweetScan, and follow topics in near-real time with saved searches
    - automatically find tweets mentioning your @username
    - record a video on Seesmic Video, and share it on Twitter immediately
    - get your Seesmic Video updates in real-time using XMPP
    - English spell checking

There are a lot more things twhirl can do to improve your experience, and it offers various configuration options to adapt to your personal needs.

Visit Twhirl Site