This is a great post that gives you a few tips on how to get the most out of your iPhone's battery. They even address my pet peeve as a bonus tip:
“Bonus tip: Stop flicking apps away!
I see far too many people flicking apps out of the multitasking tray thinking it saves their battery. It actually does the complete opposite. iOS automatically saves states so apps can launch as they were without having to restart completely. Flicking them away and then restarting them actually consumes more battery.
Compare this process to putting your computer to sleep instead of shutting it down and restarting it each time. Which method do you think uses fewer resources?”