This mashup is based on the addictive messaging medium that is Twitter. Twitter's API allows users to get hold of the latest tweets and Twitter Watch displays these as a constant stream, updating your screen every few seconds with a new tweet. (May contain foul language.)
UPDATE: Because not all tweets are in English, we've improved this mashup so that tweets can be translated into any one of a fairly large selection of languages. This is possible thanks to the Google AJAX Language API.