twtpoll creates multiple choice polls for you to post on Twitter.   Visit twtpoll here

    Ask a question of your Twitter followers and easily gather all their answers in one spot. Use TWTTRSTRM to…     * Stage a debate.     * Make a prediction. Then see who agrees.     * Ask for advice, feedback, nominations, recommendations. Gathered on one page, it’s pretty handy.   Visit TWTTRSTRM here

    TwitExplorer allows you to search updates based on the author or keywords.   Visit TwitExplorer here

    Tweetvisor is a web-based Twitter interface, that enables tweeters to better manage multiple Twitter accounts, returns real-time updates about favorite topics, news and tweets, and supports groups, tagging friends and inline video replies.   Visit Tweetvisor here

  twtvite allows you create invites to events and send via Twitter.   Visit twtvite here

    Tweetreplies uses the Twitter API to have your @replies on your account send directly to your chosen email.     Visit tweetreplies here

    Send @twitrans tweets like: en2sp I can now tweet you in Spanish! When are you coming for a visit in New York? Wait a few minutes. While you wait we route your text to our translators at OneHourTranslation.com Get the translation back in your Twitter home page: twitrans @twitter ¡Ya puedo decirte pío [...]

Knowledge Is Power: Set up alerts and track keywords in the public Twitter stream. We will monitor the Twitter tweet stream and periodically email you a digest of the tweets that contain those keywords. It’s similar in functionality to the [defunct] Twitter track feature, except that alerts are sent in an email digest format. You [...]