check out the groundspeak thread — I added my 2 cents.
Eseentially, you’re with some other cachers and you see the cache, but want to let others have the chance to find it too. So you stand somewhere away from the cache (usually at a tree, but any spot will do) and declare that you are at the finder’s tree. As others spot the cache they also move to the finder’s tree area. When everyone has had a turn at finding the cache it is retrieved and the log is signed.
It’s just a polite way to let everyone have a turn.
No to mention the teasing that goes on towards the last person who is still searching.
Bec