It's bloody stupid, completely selfish and the stats show that it's also very dangerous:
"Distracted driving is a leading cause of serious car crashes in South Australia. Inattention is reported to be the primary cause in nearly
30% of fatal crashes and 45% of serious injury crashes each year. Research shows that using a mobile phone while driving increases the risk of crashing by at least four times. The most common types of crashes associated with mobile usage are 'run-off-the-road' crashes and 'rear end' crashes.
http://www.mac.sa.gov.au/driving-distracted
I'm sure the numbers would be similar nationwide.
Dean