Now where did I put it?

You could be standing just metres away from buried treasure—but unless
you have a Global Positioning System (GPS) satellite navigation receiver you
might never find it. This is the premise of a new sport called geocaching, a
21st-century treasure hunt with a digital spin. The idea is that people hide a
stash of treasure, typically a Tupperware container filled with a selection of
goodies and a logbook. The precise coordinates of the location are noted by the
hider and then posted on a website such as www.geocaching.com, along with a few
clues to its whereabouts. Armed with their hand-held…