Mobile users need for power

The New York Times has an article: Power Users, Ready for a Refill which points out something I hadn't really thought about - the need for power when mobile. For me, even if I use my mobile all day, a charge lasts a day - more than a week on standby, my laptop lasts 5 hours (if I'm just working on documents etc) and my main mobile mp3 device is in the car so I hadn't come across this issue. But it seems people with high current devices are desperate for a charge:-)