Case 1 : xMan bunnyPunia uses his reliance handset while riding his ZMA with one hand. He does not feel any need to stop and then attend the call, lest he might miss it. Agreed he is a good rider and can control the bike, but accidents dont happen when you are in control anyways!
Case 2 : xMan Sunny lost his 14,000 bucks cellphone when he took a sharp turn at high speed on his bike. The phone was in his pocket. He knew it was going to fall but couldnt save it lest he lost the control of the bike. And at this particular instance the phone wasnt even ringing.
Case 3: xMan Sunny takes out his mobile camera phone to shoot the brand new ZX9r which just zipped past him. He must be at least on 80kmph. Luck is with him he doesnt fall and he is able to take blurred pics and go one handed admist the heavy traffic for at least 1 km.
There are innumerable cases of which I simple dont know of and which have been more stupid and fatal, especially to bikers. Most of the handsets come with handsfree still most of us dont use it. Why? With the advent of camera phones this has got to be even more dangerous. Us bikers are always looking out for exotic vehicles to shoot on the road, even if it means single handed daredevling. Well you cant mess with luck and nature boy, you never know when they turn against you!
There are more intricate details to be looked upon, like if you set you mobile on vibration mode, it means that you will get a litlle distracted wven ehen it rings, or even when it doesnt you can get many false alarms are the vibrations from the bike get carried on to your legs - the 'back of my mind' thing gets into play.
I cant afford to list down the many dos and donts at once, why not carry on this disscussion further and make it worthwhile for everyone to read and follow.
Some links from my side:
http://www.rospa.org.uk/news/releases/road/page12.htm