Geocaching is finding your way to a specific Latitude and Longitude, finding the cache (usually a waterproof container with a log and some sort of cheap prize). There are nearly 900,000 registered geocaches around the world. Most people use a gps device to get close and do some hunting.
What I was thinking is that any interested member could determine a location, set up the cache and post the exact coordinates here. If you don't have a GPS device that will give you the Lat/Lon, you can always refer to google maps for it.
It'd be a fun way to get members out and about...or to organize geocache meets.