For those of you who don't know, a geocache is a type of treasure hunt.
What you do to find them is go to geocaching.com and search your area code or city. You have to sign in to get them, but basic membership is free. They usually have lat and long coordinates which you can use a GPS to find.
Or you can do what I did for this one (if you don't have a portable GPS), which was plugged the lat and long coordinates into google earth, or similiar type map and satelite viewer, and zoomed in until I recognized my neighborhood park and figured out where in the park the geocache was.
Then I walked to that area and looked around till I found it.
Most geocaches are some type of small container: tupperware, Rx bottles, film cans, etc. with a log book or paper inside to write your name. You can see in the picture this particular geocache was a keychain fob that unscrewed, (originally probably to keep an extra dose of asprin, valium or viagra). Inside was a rolled up strip of paper that had the names of everyone who has found it. I forgot to take a pen, so I will have to go back to sign it. You can then go on line and log in that you found it.
There are thousands of these all over. My parents found one in Williamsburg when they were visiting here a few months ago. There is at least one more within a mile of my house. It's back in the woods though, so I'll probably need a GPS to find it.
It was pretty cool going on a walk in my own neighborbood, going in to a bunch of trees and finding a hidden treasure that was almost sitting in plain sight, but that I never would have found otherwise. I sense a new hobby for myself....