In October 2004 I hid a camera in a tree-stump and published the location on the internet at http://Geocaching.com . I invited people to take photos of themselves and leave the camera where they found it.
A year later I came back and developed the photos.
The result is a delightful montage of people (and dogs) having fun outdoors.
I'll leave another disposable camera at the same location, so if you'd like to be part of posterity, sign up at Geocaching, and check out the Geocache called "Only the Lawnleis" .