Learn some tips to increase battery life on your iPhone at http://blog.guykawasaki.com/2008/08/the-art-of-ipho.html. Nothing super secretive here, but great knowledge for new iPhone users.
The only thing I’d add to his guide is using BossPrefs (for jailbroken iPhones) to quickly enable and disable things like Edge, Wifi, and Bluetooth, rather than navigating through the menus. I should also note that “Airplane Mode” can make your iPhone last a few days on a full charge, if you just want to use the iPod.
