How to save battery on iphone?

I'm going camping and i wanna save my iphone battery? Please someone help i charge it overnight everyday from 6, 7pm- 7am

Http://ipod.about.com/od/iphone3g/tp/iphone-battery-life.htm

Keep it turned off unless you absolutely need to use it.

I hope that you will help this

14 Tips to Extend iPhone Battery Life
http://ipod.about.com/od/iphone3g/tp/iphone-battery-life.htm