Listen to this 'Talk of the Nation' topic
Though Scott might laugh at me, I adapt to new technologies pretty casually. Never the first nor the last, I usually get in somewhere in the middle of the pack... Or not at all, if it's something I really can't justify. As such, I don't have GPS yet... I love maps and figuring out routes, so I don't think I need it. Of course, I don't think that's true for everyone -- I'm house hunting (well, condo-hunting) right now, and my agent has a system. (They're a match made in heaven). The other place I'd love GPS is on the DC Metro buses. The devices can predict train arrivals... Why can't they do the same for busses? Turns out they can (and in DC, one day they will). Where else do you want to see GPS? And do you worry about its spread?