Spaz

Your special Twitter friend. Spaz is the open source desktop Twitter client for Mac, Windows, and Linux. Spaz is a Twitter client for users who value free, open-source software, attractive design, and customizability.

TweetDeck

TweetDeck is an Adobe Air desktop application that is for Mac OS X and Windows. It aims to evolve the existing functionality of Twitter by taking an abundance of information i.e twitter feeds, and breaking it down into more manageable bite sized pieces. TweetDeck enables users to split their main feed (All Tweets) into topic or group specific columns allowing a broader overview of tweets. To do this All Tweets are saved to a local database. The far left column will always contain All Tweets. The GROUP, SEARCH and REPLIES buttons then allow the user to make up additional columns populated from the database. Once created these additional columns will automatically update allowing the user to keep track of a twitter threads far easier.

TwitterFox

The extension adds a tiny icon on the status bar that notifies you when your friends update their statuses. Also it has a small text input field to update your status.

Twitterlicious

Twitterlicious is a Windows application that makes using Twitter more fun. It handles all the hard work, leaving you to read and write tweets with the minimum fuss. Best of all, Twitterlicious is free!

Twitterrific

Twitterrific is a fun application that lets you both read and publish posts or “tweets” to the Twitter community website. The application’s user interface is clean, concise and designed to take up a minimum of real estate on your Mac’s desktop. Requires: Mac OS X 10.4 or later: $14.95.

Snitter

A Twitter client for Mac and Window. Snitter is “Snook’s Twitter”: an Adobe AIR-powered application for twittering. Keeping up with your friends has never been so fun!

Twhirl

Twhirl is a desktop twitter client, based on the Adobe AIR platform. 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.

Tweetr

For Mac and PC. Send files to your friends, but just dragging any file on to Tweetr. Tweetr will automatically upload your file and when it is done will provide a short url to send to your friends. Use the webcam feature to show off you latest toys, bruise, haircut. To use the webcam click on the camera icon.