HootSuite is the ultimate Twitter toolbox. With HootSuite, you can manage multiple Twitter profiles, add multiple editors, pre-schedule tweets, and measure your success.
Sideline is an Adobe® AIR™ desktop application built with the Yahoo! User Interface Library (YUI). It allows users to create and group custom queries by topics of interest.
Sideline is an open source application released under the BSD license. The first beta release is out and the code is hosted on github.
gtwit is a dynamic web based client for
that supports history and personal search of your tweets by storing them on Google's cloud
features
* no install required - works in any modern web browser
* stores all tweets you send or follow on google's cloud infrastructure so you can search your tweets by person, word or tag
* allows smart completion of people or tags (just hit @ or # in the text boxes)
* supports multiple twitter accounts
@dabr is a mobile web interface to Twitter's API. It has been described as m.twitter.com on steroids, and tries to provide as much mobile functionality as possible.