I got this idea for someone to try in a car setup, i dont know if its possible, and how hard it would be to do but...
Getting 2 of those X-10 mini cameras (or something similar) and placing them in the back of the car so that they cover each blind spot, and buying a small 4" LCD, and then wiring up something so that when the driver flicks the turn signal either left or right, the LCD screen switches to the corresponding blind spot camera. This would make changing lanes a bit safer eliminating the over the shoulder blindspot check.
That was my final project at tech school. I put a rear camera and a small pinhole camera into the rear and passenger mirror of a Little Tykes car. The idea was to have the blindspot camera on all the time and when you put the car in reverse the rear camera would show and an overlay (done in Visual Basic) would display distance to an object using ultrasonic sensors. This is actually what started the idea to put a computer in my car. Everything worked in the end but still don't have the setup complete in my car. It never seems to end.
I like the idea of a couple smaller LCD's (say 3") in the A-pillars.
I got the cameras from Supercircuits. They are good cameras and cheap. Pretty cool stuff they got there.