Mesaib Labs released a new desktop client, Hummingbird for cross platform desktop which comes in different versions. Grasp ahold of the full potential of the social networking phenomenon.
Hummingbird II – Lite or PRO Editions
Hummingbird Lite or PRO is an upgrade from the FREE Client version. By upgrading to Lite or PRO your business can automate the following and unfollowing practices that usually result in headache soonafter the start of using Twitter.
There are many things to know about when following or managing your network, and the developers of Hummingbird have …

 
Tho.st provides file hosting/sharing service via Twitter, The user simply uploads the file with short description and viola the link is send via Twitter to the other users. It’s a simple web app. Check it out: http://tho.st/

TBUZZ is your browser’s bookmarklet is an easy way to talk about the websites you visit on Twitter. TBUZZ makes it easy to tweet the page you’re visiting or keep track of the buzz around it.

Seesmic Desktop has just  been release, You should be able to update the current version on your desktop by restarting the application and it will update automatically or alternative download it from http://d.seesmic.com/seesmic/SeesmicDesktop-0.2.a ir
New Improvements

Add your Facebook account
Aggregated timelines for Twitter and Facebook accounts
Now supporting Twitgoo and Posterous in addition to Twitpic to share images on Twitter
Cleaner column look and feel
Optimized use of space to display more tweets
More tooltips on buttons
Improved error handling (especially for connection problems)
Improved pre-selection of “SHARED as” account to reply or retweet from
Remembering your preferred image …