Twitster is an open source PHP application that enables you to display tweets of everyone you follow in Twitter in any website.
And, it can filter tweets by a hash tag (#example) which makes it possible to create a Twitter-based group or community in the website.
Twitster comes with a web-based installation wizard that helps setting up the system quickly.
It currently supports one hash tag to be used but features like multiple has tags & @reply linking are expected in the next release
Requirements: PHP 4+, MySQL 4+
Compatibility: All Major Browsers