I've spent the evening skipping the gym and I'm doing something I'm not particularly proud of: playing Mafia Wars on Facebook. A new friend of mine, Jean Bradberry suggested it.
I haven't been playing long, but I'm already noticing some things about it: It uses simple psychology to reinforce your behaviors. It does this primarily by using game-play to improve your game character and earning money. The catch though, is you have to keep returning to the game for more later on. Your character can also acquire different items to assist in you (which in turn require more money and more gameplay).
The whole premise reminds me very much of Blizzard software games, primarily Diablo 2, and World of Warcraft, where developing your characters becomes an obsession over time. Needless to say, one can easily purchase items in gameplay with your credit card (which I assume is how Facebook and/or the Mafia Wars Game developers make money).
Anyways, I've bought a bunch of abandoned lots for income, and I expect to be selling them soon enough for some commercial lots where I'll build some apartment complexes. My character is still a low level "street thug" where I'm busy mastering the "mugger" skill and the "corner store hold-up" skill (I've already mastered "collect on a loan"). If I build 34 apartments I can earn the "slumlord" title. But I'm still only level 6 (I can expand to Cuba at level 35).
My friend Jean claims its an interesting and intelligent game worth giving a try at. He says it teaches you a lot about psychology and interpersonal relationships. So I'll see where it goes.