Can somebody please explain this in non-technical layman's terms...thanks! Sounds like fun!

http://www.geocaching.com/about/credits.asp

The gummint thought that for anyone other than them to know exactly where they were was detrimental to national security so they made it such that getting a clean GPS signal required some piece of equipment only they had. Sort of like a cable descrambler for premium stations. President Bill said, "Bleep that bleep!" and cleaned the signal up for everbody.

Thanks, Faldage!...I think.

So has anybody here ever been involved with this Geocaching sport/game?

No, but now I see what was going on with the wooden Indians and the mobile 'phones!!