Trimble - All About GPS

Here's a cool tutorial on how the GPS system works (I say cool, but it'll probably only be cool if you're a geek). I've been trying to find a cell phone that has a GPS reciever in it, and it looks like Nokia and Motorola have a couple, but nothing too great yet. Hopefully some day soon. GPS technology seems like a good thing to invest in since there are so many things the system could be used for.