satellite-navigation

Is there an API or SDK for TomTom satellite navigation devices that would let me access them from Windows?

I was given a TomTom satellite navigation device (XL 30) for Christmas and I've been wondering recently if it is possible to use it as a location sensor for my own programs on my (Windows 7) laptop. Does anyone know if there is a published API which would allow me to do this? More specifically, how can I query it for my current location...

How does route finding software work?

I'm asking at a pretty high, language independent, level. How does route finding (as found in Google Maps 'Get directions' or a GPS) work? I can't believe it tries every conceivable route and chooses the shortest/fastest etc. There must be some logical way of finding the best route given a start and end point. Any sort of explanation w...