Geocaching - what is it?

Geocaching is a high-tech treasure hunting game played throughout the world by adventure seekers equipped with GPS devices. The basic idea is to locate hidden containers, called geocaches, outdoors and then share your experiences online. Geocaching is enjoyed by people from all age groups, with a strong sense of community and support for the environment.

Useful links and resources
Telling students to get lost has its rewards (Gerard's article from NZ Interface Magazine)
PDF file: A guide to geocaching
How can I get involved?Get a GPS device (from Dick Smith) or use your iPhone - download free GPS app

So how can I do this with my class?* Resources from ulearn09 on how to use it with class:

Geocaching with @gmacmanus