Geocaching Games?

I'm sure there's a place over at groundspeak's forums, but that place is like Texas - too big and too many people. Don't care to go there if I don't have to. ;)

I'm looking for some ideas for geocaching games. I'm wanting to set something up with some of our parks interpreters so that we have a geocaching activity some time. I want to take up 45 minutes to two hours. I've lightly outlined a scavenger hunt approach. Any ideas, anyone else?

Geocaching Team Challenge

There are teams of up to 5 people per GPSr. Make them sign up before hand.

The team’s Navigator will be the one in charge of the GPSr. The team may elect to change Navigators whenever it wants.

Each team may have an interpreter (GPSr owner) to act as a walking GPSr manual if a real manual is not on hand. Interpreters may give limited verbal help on the use of the GPSr, but MUST NOT PUSH ANY BUTTONS! They may also be used as mules.

Teams will only be supplied with paper maps if they ask for them.

Interpreters will have already placed as many caches as there are teams. In case of only two teams, I’d suggest setting up caches with at least two stages.

Each team is given a different starting coordinate that leads to the first cache. This cache may give coordinates for the next stage or the coordinates of the other team’s first cache. This goes on until all of the caches have been found by at least one team. Tokens or keys to the next cache may be left to insure that the teams really found the caches legitimately.

Whichever team finds them all first wins.