BountyNetwork is a mashup which allows you to put out "bounties" or listings for services or items on pretty much anything you want, then tag that bounty to your local community on a map. The focus is on "providing you with a platform for user-to-user commerce, meaningful recommendations based on your location, and the ability to expand your search areas based on what you're looking for."
Here are some example "bounties" that can be found on this Google Maps mashup:
Wanted: 2 Tickets For Wizards Vs. Orlando Nov. 5th
Wanted: Free Standing Wine Cooler
Wanted: Artist To Do Oil Portrait Of Infant