Four tips for better iPhone battery life

Does it improve the battery life to throw it at your wife? (just wondering if that was covered)

Simply throwing your iPhone at your spouse however, is not an approved methodology. Thanks, David Pogue!

Sometimes I wonder if multi-tasking should be opt in instead of opt out. Maybe there could be a system preference for switching this behaviour. Like suppose when you 1-click the home button it actually kills the app. Or if you want it to stay running in the background you 2-click the home button. Basically reverse the current behaviour of the home button regarding multi-tasking. A kill app 1-click should be the default and a 2-click an intentional "I want to keep this app running". It seems counter intuitive to have to 2-click to begin killing apps one by one especially with some apps that of course you would have preferred just quit by default instead.

Background "phone" apps like Skype really kill the battery. Those are the few that really are allowed to run in the background...kill those and your battery will suddenly last MUCH longer.

Suggestion of jailbreaking the device here. Like SuburbanGiant said installing SBSettings, and the awesome add-on for it called "Remove Background" which will close all the background apps with one touch!

You can also manipulate all the radio functionality from here, respring, power off, and everything else.

And to throw in my two cents on push notifications: The more you have setup to On the more your screen lights up when getting notifications. This in itself will obviously use more power, when your phone is in your pocket not being used and it keeps lighting up for a minute each time you get a new notification.

Only leaving on the apps you want notifications from, will decrease the times your phone tells you about things and in turn, will increase your available battery.

Personally, I leave twitter and facebook on, everything else has the feature disabled. Those 2 apps alone, dependent on how much you use them, can wipe out your battery anyway!

One thing regarding Push. You can go into Settings > Mail > Fetch > Advanced, and enable or disable Push on a "per account" basis.

According to SBSettings (jailbreak app) the more apps I have open on my iPod touch 3G, the less available memory I have (max of about 160MB), and the more sluggish my iPod runs. And the only ways I know to speed up my iPod are to quit apps, restart, or respring/use SBSettings to kill selected processes (jailbreak only). So while apps may not be fully running in the background, they still hog quite a bit of memory if you have a lot open. This obviously affects older devices more (they have less RAM).

My tips for saving battery life, especially when driving without a charger, are to (1) turn off WiFi/3G/Edge/Bluetooth. This is assuming that you're not using a navigation app that requires an internet connection or that you're using a BT headset. (2) Turn off the screen if you're not looking at the map. I use Navigon, which is pretty good about telling you where to turn before you reach the intersection. (3) Turn off push email. This works for my Gmail account, but the Exchange server I use for work still gets email for some reason. (4) Turn off push notifications. Some commenters have mentioned that this really doesn't improve battery life, but I do it to reduce the amount of data coming in because I get pissed off at the duuh-dee-dee-duhh coming in through my speakers. Although if you already have data turned off, that isn't much of an issue.

As for daily use, I browse the internet, make phone calls, text, take pictures probably about as much as any other user and usually end the day with about 60% remaining. I don't really do much to conserve battery life, just have email and Bluetooth turned off. While I could easily make it two days without charging, I almost always charge it at night because it's nice to have a full battery when you have to make that surprise trip to help grandma set up her new iMac.

I pretty much have done what others have said. Killed notifications, med-low brightness, no Ping, dump everything out of my active app tray. The one that works the best? Airplane mode. Unless I am waiting for a call, I just slip my iPhone into Airplane mode. Turn it back once an hour or so to check up on things and then off. Then I have plenty of battery life when I want to kill a few hours watching a movie on NF.

Apple needs to make a better battery. Simple as that. I'm not turning down my screen as low as possible to where i have to strain or constantly toggle in the settings. That diminishes the experience. Yes, BT, and wifi, radios in general will wear down any handheld. But the iphone is about a 5 hr device. After that....with any WORKING person.. all confidence is gone if you're not close to a power source. And having it plugged in isn't "cool" either.
What do you guys think?