I spend a lot of time on Secondlife... A LOT of time...
Secondlife is a 3D-virtual world where you can be whatever you want to be. Though it's considered a "game", there is no manufactured conflict, no set objective and no "winner". However, there are many games within Secondlife, like Greedy, Cheesy and Yahtzee. There are also RPG's like family and vampire (which is called "Bloodlines") role-play. You can take classes in a virtual classroom, or visit the Titanic, and go to The Haunted Mansion at Disneyland, though for copyright reasons it's not called Disneyland.
Everything in Secondlife was created by the players, and accuracy is absolutely amazing. Secondlife is like Barbies for grown ups. Like i mentioned before, u can be whatever u want, a person, a furry, a gargoyle, a cat or a dog, just to name a few.

This is me in Secondlife
I am a prodigy in SL