Second Life
http://secondlife.com/whatis/economy_stats.php Second Life is a 3D world where everyone you see is a real person and every place you visit is built by people just like you. Second Life is an online virtual world developed by Linden Lab. It was launched on June 23, 2003. Second Life users can interact with each other through avatars (Also called Residents). Residents can explore the world (known as the grid), meet other residents, socialize, participate in individual and group activities, and create and trade virtual property and services with one another. Second Life is intended for people aged 16 and over. Second Life is used as a platform for education by many institutions, such as colleges, universities, libraries and government entities. Avatars can communicate via local chat, group chat , global instant messaging and voice. Avatars may take any form users choose ( human , animal etc) or residents may choose to resemble themselves as they are in real life.