From Nature:
Next month, biologist Erik Born will be wielding a crossbow and firing satellite tags into the hides of walruses, having manoeuvred his rubber dinghy through the pack ice off western Greenland. By tagging the walruses, Born will be able to track the animals’ movements and behaviour from afar over several years. He will keep an eye on them using the same free Internet tool that has opened the eyes of millions to the possibilities of digital geography (and the sight of their house from above) — the Google Earth virtual globe. When the walruses migrate in the spring, Born and anyone else with a copy of the Google Earth software and a decent Internet connection, will be able to follow their westerly path to Baffin Island or the Canadian coast, and their return.
To the casual user, of which it has attracted millions since its launch last June, the appeal of Google Earth is the ease with which you can zoom from space right down to street level, with images that in some places are sharp enough to show individual people. Its popularity with a growing number of scientists lies in the almost-equal ease with which it lets them lay data with a spatial component on top of background imagery — a trick they can repeat with multiple data sets. By offering researchers an easy way into GIS software, Google Earth and other virtual globes are set to go beyond representing the world, and start changing it.
More here.