What is Twitter?
Here is a definition as quoted from wikimedia.org
Twitter is a social networking and micro-blogging service that allows its users to send and read other users’ updates (otherwise known as tweets), which are text-based posts of up to 140 characters in length.
Updates are displayed on the user’s profile page and delivered to other users who have signed up to receive them. Senders can restrict delivery to those in their circle of friends (delivery to everyone being the default). Users can receive updates via the Twitter website, SMS, RSS, or through applications such as TwitterMobile, Tweetie, Twinkle, Twitterrific, Feedalizr, Facebook, and Twidget, a widget application. Four gateway numbers are currently available for SMS: short codes for the United States, Canada, and India, and a United Kingdom-based number for international use. Several third parties offer posting and receiving updates via email. By February 2009, Twitter had 55 million daily users.
Interested? Then start Twittering! Register a profile at Twitter.com