When I was a bike messenger we had those giant motorola/nextel rubberized brick phones. It would have been impossible to do the job without using the 'chirp' 'radio' function while cycling.<p>I recall a story of someone dropping one in traffic. It bounced off the pavement and was hit by an oncoming box truck. He retrieved it from the sidewalk and continued on without issue.<p>Not sure if that would be possible with today's handsets.<p>We were not exactly popular with motorists. That kind of behavior would not have gone over well in Singapore.