www.project-entropia.com
Its a free online multiplayer game set in the future.
Free = Game is free, and you can start with nothing, but if you want to get started quicker, you can buy stuff with real money. You can be anything you want - Real-estate, hunter, trader, miner - you name it.
The cool thing is; the money you make in the game, is REAL money - you can take them out of the game. Last month someone sold a Housing project for $100.000,- in REAL cash.