Geocaching in schools

I have been using geocaching as a way of familiarising my students with their local environment. Using GPS navigators, we search for the hidden treasure planted by a fellow, keen geocacher.
My next step is to adopt a local environment, get the kids to maintain it, make permanent posters created by the students to inform tourists about the area they are visiting and then create our own geocache linking all our work together and added to the geocaching website.
I have a ning called S@CALEs that shows our progress.
Does anyone else use geocaching in their schools?