I was just reading some more of Jane McGonigal’s book, Reality is Broken: Why Games Make Us Better and How They can Change the World, and came across a game called Chore Wars. Basically, a household signs up and each person creates a characters. You develop the character by gaining XP (experience points) and virtual gold by epic quests. These quests are actually doing household chores in real life. Chore Wars sounds a little crazy, but given her analysis of why games make us happy, it actually seems plausible.
Here is a video about Chore Wars: