Abel00: Dead on Moska, even now, it seem every Iphone generation gets more efficient but my battery life is shorter because I have more uses for it and it lets me do more powerful processes.
What you are describing is known as Jevons Paradox and it explains why energy efficiency won't save energy: Since appliances and applications use less energy, we'll use more of them, overcompensating the energy savings.
See the Wikipedia article about Jevons Paradox: http://en.wikipedia.org/wiki/Jevons_paradox.
(I'd wish energy policy would understand this and lower expectations in energy efficiency regarding CO2 emissions etc.)
