My newest challenge is to get the smart-phones and hand-held GPS out of the kids hands. As these are usually quite necessary for geocaching, I am working with the adults to coach the scouts on heading and distance using a smart phone (which the scouts can't see) and they have to use a compass to navigate.
So far I have used only map and compass to find the caches I've done. It does make it much more challenging! As such, I have tried only caches that I have some chance of getting a bearing from a known landmark (e.g., building, creek junction, tower, lake, etc).