Twitterment - A search engine for Twitter powered by Google search.

Twitter Who - Using this, you can search for multiple queries on Twitter at one go.

Hello Txt - This service enables you to update Twitter, a host of other micro blogging sites, and social networking sites with one click.

Link Bunch - Need to share more than one link in a tweet?

Twitter Cal - This service allows you to post events from your Google calendar to your Twitter accounts.

Twitter Feed - This tool allows you to send your blog atom or RSS feed to Twitter.

Twitter100 - Just like in your personal start pages, this tool will allocate a box to each of the people you follow on a single page and display their latest tweets.

Twitterator - Twitterator enables you to follow a group of people at one go.

Twitxr - Another neat way to post a picture on Twitter, Facebook, or Picassa.

Tweet Channel - You can add Tweet Channel as your friend in Twitter to help you channel your various posts.

Out Twit - A tool for Outlook that will send the latest tweets from your friends as incoming email messages.