Battery life
There will be somebody one day that will explain in a scientific manner the reason why the only way to restore life of the battery of iPhone is reset-DFU, and not all those useless tips that have only a temporary placebo effect?
For two years who carry out experiments on the iPhone 3, 4 and 3G and this is my result: to revive the battery needs to be done Reser-DFU.
iPhone 4, iOS 4.3.3