what is second life?
Second Life is an on-line, 3D world. Its key feature is that residents can own land, and can build and script items -- walk round Second Life and you will find no end of shops full of stuff that people have created (some of them amazingly good) and are selling.
Yes, it has its own economy.
If you just want to experience the world, dance in the clubs, chat with the other residents, gamble, even have cyber-sex (it has 'mature' areas and 'PG' areas...guess the difference), you can join for free.
If you actually want to own land and build your own residence, you need to pay, and there is a monthly charge (which varies according to the size of the area of land you own). It isn't particularly expensive, though.
I've been a resident of Second Life for quite a while, with a couple of plots of land, but recently I created a new character who I am going to use to simply explore the whole of the Second Life world and chart what I find -- check out his page for more information.
Second Life and Linden Lab are trademarks or registered trademarks of Linden Research, Inc. All rights reserved. No infringement is intended.