Twitter, the free social networking and micro-blogging tool that is built on instant messaging technology, continues to be one of the largest and fastest growing member-driven sites on the World Wide Web. Launched in 2006, Twitter appeals to a wide variety of people, from typical web users and professional bloggers to high profile figures like celebrities, presidential candidates, and information technology leaders.

Twitter's simple interface offers a convenient way to send short text messages ('tweets") of up to 140 characters to other users ("followers") that you allow into your network. They can be about any subject and include interesting web links or just answer the question "What are you doing?"

All you need to do is create an account at Twitter.com with a user name and password, personalize your profile, enter your first tweet into the text field on the home page, and click "Update." Your tweets are listed on your profile page in reverse chronological order (called a "timeline") like a series of short blog entries. They are also sent to your followers' home pages and can appear in the public timeline for all to see if you wish, or just be sent to one particular user. To follow others, you must locate their Twitter page by clicking on their username in a tweet, using the search feature, or using the link in the email notice that is sent to you when they start to follow you. Then just click the "Follow" button.

Since Twitter is web-based, you can tweet from your desktop, laptop or any handheld device that has instant messaging technology. To receive messages via your mobile phone, just go to the Devices tab on the Settings page of Twitter.com and enter your phone number. Twitter doesn't charge for its services, but depending on your phone contract, your carrier may charge you text message fees. For more information about using Twitter, view the short video below.