Extend your iPhone Battery
Do you find that you use your iPhone a lot during the day when you are out of the Office, and you find that the Battery runs out.
You could follow a few simple steps that might extend the battery life. This might compromise your usage, but are worth trying.
Reduce the amount of times you fetch push email. To do this go Settings>Contacts>Calendar, change the Fetch New option to Off or Hourly.
Turn 3G off, to do this go to Settings> Network and slide the enable 3G button Off.
You could also try turning Location Off, to do this go to Settings>General.
Doing these three things should extend your battery life.