What is Second Life?

Second Life is a 3D multi-user virtual environment built and owned by its residents.
Since opening to the public in 2003 it has grown explosively and today is inhabited by 318,118 people from around the globe.

Videos about SL

Google Tech Talk (1st March 2006) Glimpse Inside a Metaverse: The Virtual World of Second Life
Linden Labs demonstrate the Second Life program to staff at Google

TechTV (31st July 2004) Second Life Animation Party
Excerpt from a television explaining the concept of Second Life