Battery life is probably the biggest gripe for most iPhone users, so here’s my first tip to help improve it.

iAds is a service Apple provides that delivers the adverts you see in ad-enabled apps. While you can’t turn this off, the service by default tries to provide you with “useful” ads based upon your location. Checking your location and finding appropriate adverts does obviously use more processing power and bandwidth, and thus more battery.

To turn this service off, go look in the Settings app under :

Privacy -> Location Services -> System Services -> Location-based iAds -> Off

Bonus tip – on this same screen turn off Frequent Locations, as this also apparently drains the battery more quickly.

(Thanks to a Genius at my local Apple Store for both these tips!)