I think Bill Gates wrote in his book "The Road Ahead" back in 1996 that one day we would have wallet PCs (the size of credit cards) with built in GPS. The information would be fed into government computers for storage and the government would know where each of us was within a few feet at any time in our lives.
It has been a while since I read the book but I believe he thought this was a good thing since the information could be used to prove you were elsewhere when a crime was commited, etc...
It's a brave new world,
