How to Register My Device in the iPhone Developer Program
To successfully build and test apps for the iPhone, you’ll need an iPhone to test them on. Your iPhone can get this test-ready status by registering it with the iPhone Developer Program as part of your account. To register your device you’ll need to determine its unique device identifier (UDID), and then link it with your existing developer account.
1 40 Digits of Fun
Every iPhone has its own UDID that you can find through iTunes. After connecting your iPhone to your PC and starting up iTunes, click on your device in the menu toolbar. In the Summary window, click on “Serial Number” -- this doesn't look like a button, just text. When the text switches to say “Identifier (UDID),” press “Ctrl-C” to copy the 40-digit UDID. Open up Word and paste the number into the document by pressing “Ctrl-V.”
2 Registering Your Phone
Head over to the iOS Developer Center (link in Resources) and sign in. Click on the “iPhone Developer Program Portal” menu item and then click “iOS Provisioning Portal.” In the Devices tab, you can add a device by giving it a name and pasting in its UDID. After you press submit, your device is officially registered with the program and ready to help you developing great apps.