Nice idea.  Next time you are in Town, and you got a great parking spot, but since you are leaving, why not save the spot for your fellow android device owners, by using this Open Spot app by Google

Open Spot works by letting people who are leaving parking spots share their spots with people who are searching for parking.

Start helping others find parking, and together we'll all save time, save gas, and reduce pollution. Like to keep score? The more open spots you mark, the more parking 'karma points' you'll get.

Couple of Frequently Asked Questions

* How large an area will Open Spot show me available parking for?

Open Spot will show you parking spots located within a ~1.5 kilometer (km) / ~.9 mile (mi) radius of your location. As you move, Open Spot will automatically refresh to show you parking spots within a ~1.5 km / ~.9 radius of where you currently are.

* How long are marked spots displayed in Open Spot?

Spots are removed from the map after 20 minutes. We know that 20 minutes is a long time for a parking spot to stay open, but we think that more information about available parking is better than less.

check it out folks, and download this cool app for android