Here's our plan...
When you find a rock, take a picture of the rock and yourself, or the place where you found it and post it our facebook page (https://www.facebook.com/rockinconcordia/).
Then, place it in a different location for somebody else to find. Try not to hide it too well where it can't be found but in a place where it's a little bit noticeable.
If you want, give the community a clue as to where you placed it and send somebody else on an adventure!