collision avoidance for cell phone walkers (and cyclists (and drivers))

here's the thing - you're walking along and suddenly someone crashes into you - normally, humans use eye contact to avoid this, but nwoadays all humans are only eyeballing their smart phone screen so the obvious thing to do is to give the phone
the awareness its about to hit someone and have it beep (faster and faster as you get closer - like the parking radar systems on fancy cars and airplane collision warning systems do)

this could be made very ergomomic with camera phones in that as you get quite close, your phoen could show you some eyes and have them look the way you should go (the other persons' phones having made sure they do the same so you don't all go the same way in that collison avoidance dance you sometimes see) _ actually another verison would be one that shows you the person you are about to walk in to is a friend and maybe you should say hi rather than texting/emailing them:)

this could extend for cyclists so they no longer need to look where they ride
and drivers too in cars and buses...

then eventually the phones could just do the driving for you

and we could all just stay at home...