GPS is no one trick pony.  Long used for determining location, there are now numerous applications such as geo tagging of photos, social updates and now for measuring your carbon footprint. The software, wittingly called Carbon Diem (a play on the Latin carpe diem, which roughly means ‘seize the day’), deduces your mode of transport by leveraging what GPS infers.  For instance, let’s say you’re traveling at 10 mph on an open road.  It’s probably safe to assume that you’re traveling by pedal power.  Traveling 100 mph?  Ferrari, and burning fuel like crazy.  No doubt historical information and other variables help to draw a conclusion.  Reports show that the software, which has been tested on Blackberries and Nokias, has shown almost 100% accuracy.  Unless of course you’re traveling on a bus, which apparently applies too many variables for a sound conclusion.

[Popsci]