For scouts that have never heard of caching, we have put on a few scout geocaching demonstrations and have had good luck with putting together a series of temporary (non-published) caches on scout camp property or even the private property of a scout family. The advantage is there is no driving around, the group can do a bunch of caches, it’s easier to control, and you can control the content and quality of the caches. For instance, you can put scout swag and trinkets into the caches.

You can do somewhat the same if you find an area that has a “power trail” of caches, but you cannot control the cache content and quality to the same extent.

I don’t have an answer to your GPS rental question. I might suggest that you poll your troop parents to see who might already own a handheld unit and you might be surprised at the result. Or local cachers might be willing to help out.

Nothing too complicated.

Basically, we’d hide a few caches of various sizes, with scouting trinkets in the larger ones. We’d program the coordinates into the GPSr units, and fortunately we have collected a few units ourselves over time so we had enough to create small groups of scouts.

After a brief explanation of coordinate location in general–i.e., every point on the globe has a set of coordinates–and an explanation of geocaching, we’d lead the groups into the field until they were comfortable enough with the GPS to give it a go themselves.

We’ve done the same thing with maps for orienteering demos. It doesn’t have to be complicated.