"Art Abandonment is a group designed to encourage random acts of art, left in various locations around the globe. The idea is that folks can make something and leave it for a lucky unsuspecting person to find. Artists can then post locations and photos of abandoned goodies…and finders can let everyone know that they are the lucky finder!" Doesn't that sound like fun?
"So leave some art. Leave a contact email for the finder…and if you get notified share the message with this group. If you prefer you can use the contact email: firstname.lastname@example.org we'll be checking it often and share the results. Here's an intro page on Typepad for full explanation: http://michaeldemeng.typepad.com/art_abandonment/