Perhaps, gradually, most travelers have started to assume that announcements made on airplanes to turn off electronic devices at launch and limit them to approved functions afterwards are anachronisms. The thought that the exercise in caution is unnecessary is reinforced by the flight attendants', by now, silly instructions on how to use seatbelts, which usually happens at about the same time as the cell phone warnings.
While it's true that somebody who doesn't know how to put on a seat belt shouldn't be traveling alone, the case against use of electronics on airplanes still holds water. A story from The New York Times notes that it is highly unlikely that an iPhone or an Evo will cause an accident. Highly unlikely, however, means exactly that: highly unlikely. It doesn't mean impossible.
The issue is something of a higher priority simply because of the exploding number of devices and the wider variety of tasks they perform. It's unclear in many cases what is okay and what is not, and many people err on the side of little caution. The good news, according to the story, is that newer planes are better shielded against interference. The bad news is that the protection that exists in older aircraft, which was weak to begin with, is likely to have eroded over time. WiseGeek has more background.
Perhaps motivated by high profile incidents during the past few months in which celebrities Arianna Huffington and Josh Duhamel got into trouble for using their cell phones on planes, MSNBC did a nice survey of the international situation. The bottom line is that ability to use mobile devices without breaking the rules differs around the world.
Most of the wired planes are manufactured in the U.S., the story says, but it still is not legal to use the cellular network. VoIP is not allowed by any airline, though it is not illegal. Inside Tucson Business offers a good rundown of the access status of major U.S. airlines and its findings suggest that Delta is ahead.
The reality is that a good deal of the resistance to full cell phone use on airplanes has nothing to do with safety fears, though they are a real issue. One point of contention raised by BuzzFeed is what 500-miles-per-hour roaming would do to cell tower operations. Even more pressing is the social element: Do people want to change the rules to risk sitting next to people engaged in long distance business meetings, domestic partner quarrels or teenager gossip?