First i was on yahoo messenger on my iphone and the suddenly the screen turns white and i didn't even drop. I tried using the home button + power and it didnt work. i tried to plug it to itunes nothing happened. I REALLY NEED HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Try holding the sleep/power button down while holding the home button down for a few seconds. This should reset your iphone. If all else fails, call Apple!