The iPhone comes with Google Maps pre-installed (called "Maps" on the phone). If you want to make sure you have the latest version of Google Maps on your iPhone, you will need to download a new version from the iTunes store. Apple will let you know when a new version is available, and you can install the latest version directly onto your iPhone. You can also download the new version onto your computer and then transfer it to the iPhone.
Updating Google Maps From the iPhone
Tap the "App Store" icon on your iPhone. The App Store will load.
Tap the "Updates" button at the bottom right of the App Store screen. All of your installed apps that have updates available will appear on the screen. If "Maps" is listed, then there is a new version of Google Maps. If it is not listed, then you already have the latest version installed.
Tap the "Get Update" button beside the "Maps" icon if a new version is available. You will be prompted for your iTunes Store password.
Enter your password and press "Okay." The Google Maps update will download and install itself.
Updating Google Maps From Your Computer
Connect your iPhone to your computer using the docking connector.
Start iTunes, if it is not already running.
Click on the "Apps" button in the menu on the left side of the iTunes screen. At the bottom of the Apps screen, you'll see a button labeled "Check for Updates."
Click on "Check for Updates." If any of your apps have updates available, a pop-up window will appear that says: "Updates for some of the applications in your iTunes library are available. Would you like to view the available updates now?" Below this will be two buttons: "Cancel" and "View Updates."
Click on "View Updates." If "Maps" is listed, then a new version of Google Maps is available.
Click on "Get Update" beside the "Maps" icon. The new version of Google Maps will download.
Click on the name of your iPhone in the menu under "Devices" and then click "Sync." The new version of Google Maps will be transferred to your iPhone.
Things You'll Need
iPhone dock connector