It doesn't have any arms - how is it going to hold a cellphone?
I doubt it, last time I checked the kinect had a very low range, below the 4m mark I think, If you stand too far away from the sensor the magic fades away.
A nearsighted self-driving car you say? Where's the harm in that? :)
infrared. This is why Grand Challenge cars used lasers, video, radar. No infrared, and ultrasound didn't succeed as well.
Turning your own car into a driverless car for less than $200 would be quite novel. (I don’t think the Kinect is ideal or all that useful for this task, it would be very revolutionary if it were, though.)
Price is important. Price can be the only thing that’s different about something and it can still be revolutionary.