Prediction
In five years every new car will come equipped with multiple cameras. Not so that the authorities can watch you, but so that you can watch the authorities and other drivers. The cameras would record what's ahead and behind and to the sides of you, and possibly even inside the car. For instance, a cow orker just got pulled over for rolling through a stop sign, despite the fact that his car rocked back when he stopped (he says). Imagine if he had it all on film, including the interaction with the officer; he would have saved himself a ticket. (Mi amigo Mike also just had an encounter I'd love to see footage of.) It would also be useful for absolving yourself of guilt in accidents, and for recording break-ins and vandalism. There's at least a dozen times in my life I can think of where this would have been great. Digital cameras are cheap, and are what makes it all now feasible -- you'd only have to store the last five minutes or so of what was happening around you.