Fourocity is a game that lets you own your little neck of the woods by buying and selling local venues based on their social popularity.
Here's how it works. Log in via Foursquare. You start with $50k in your bank account. How nice! Now do some shopping.
Venues that haven't been purchased are evaluated based on the number of check ins they receive per day. Click on an area of the map near your favorite venues. You can see the predicted value of businesses, or appraise those that haven't been checked out yet.
Pick a place that you think has a steady supply of check-ins. If you have enough money, buy it! Every check-in at that venue from now on will earn you $1000 bucks.
All that income goes back into your cash supply. Of course cash is a poor investment, so when you can, buy more stuff! Earn enough to buy bigger venues before anyone else!