You're not even half way through the day and your phone only has 15% of its battery left.  Arg!  Here are 7 ways to give your battery more life on your iPhone, Android, or Blackberry

Beware of location services

Apps that tag your status updates with GPS data, or find good deals in your immediate area drain your battery.  Opt out of that option.

Watch for push notifications.  

Each time a new message pops up on your lock screen, your phone lights up, beeps, or vibrates.  That takes a toll on your battery.  

Use 'airplane mode.'

Using your phone in this mode will stop it from constantly searching for a network.  Beware, though, that you can't make a call when you're in this mode.

Clear out apps.  

Even if you're not using an app, it can run in the background.  On android phones, go to your 'manage applications' screen and see what's 'running.'   Go down the list and force stop whatever you're not using.    iPhone users can quickly push the home button on the bottom of the phone twice to bring up a row of apps currently open, then hold your finger on one until they all start jiggling.  Tap the red 'minus' icon to close the apps completely.

Lower the brightness

Obvious but easy to overlook.  

Turn off wi-fi

The phone will constantly sniff around for wi-fi when you're not connected to wireless internet.  This is a battery drain.

Keep it cool

Batteries discharge more energy when hot.  Don't carry it in your pocket and never leave it sitting in direct sunlight.