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) and Mac OSX
* connects to multiple Twitter, laconi.ca, Friendfeed and seesmic accounts
* notifications on new messages
* shorten long URLs (using snurl, twurl or is.gd)
* cross-post twitter updates to Pownce and Jaiku
* post images to TwitPic
* search tweets using Twitter Search and TweetScan
* timeline filtering
* color schemes
* automatically check for new versions
There are a lot more things twhirl can do to improve your twitter experience, and it offers various configuration options to adapt to your personal needs.
Twitter users of TweetDeck, check this out. Facebook Connect and Seesmic Desktop is a dream application for the frequent status updater, group lover, and social media meme tracker. Has multiple columns that can be rearranged via drag and drop, customizable groups, Twitpic functions, etc.