36-hour autonomy for the iPhone

or how to ensure the best possible battery autonomy of an iPhone: 36 hours of operation.

As a matter of fact, the iPhone battery seems to be its weak point as it seems. But Guy Kawasaki explains us that -for the best part- it comes from some options that eat a lot of power (WiFi, BlueTooth and geo-localisation ) and they should not stay in full/permanent operating mode.

Simple, obvious, but useful to repeat.