I did a geocaching day with our Cub pack back in May. We didn't have any GPSr's to give out, but most families either had one, used a smartphone, or teamed up with another family that was equipped. We did a 20 minute classroom introduction, then went out to the church property to find a few that I had hidden so that everyone could get their feet wet.
Then we divided into family/small group teams and everyone went their separate ways. We're fortunate that our Council office has hidden 10 caches in each district to celebrate the 100th anniversary. So I gave each team a list of the ten caches in our district and sent them out to find them. Anyone who found all 10 got a cool geocaching patch and a Scout-to-Eagle geocoin as a prize.