December 21, 2005 In early 2005, a small group of hardcore GPS geeks (who were tired of their GPS devices not working in dense cities, urban canyons, indoors, etc) got together to come up with a ...

“OH DEAR! OH DEAR! I SHALL BE LATE!” That’s what the White Rabbit said in the opening chapter of Lewis Carroll’s Alice’s Adventures in Wonderland just before checking the time on its pocket watch.

Whereas animals are adept at navigating by myriad means, such as smell (salmon), magnetic fields (pigeons) and the topography of the ocean floor (dolphins), humans do so mainly by observing landmarks ...