www.Twitter.com

Fist....
visit me at http://twitter.com/agus3anto
Twitter is a free 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 email, or through an application such as Tweetie, TwitterFon, Twitterrific, Feedalizr, and Facebook. 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. Twitter had by one measure over 3 million accounts and, by another, well over 5 million visitors in September 2008, a fivefold increase in a month.