Step 2: Sign out of your default iTunes account.
Step 4: Search for ‘Angry Birds Go!′, or view the top free applications.
Step 5: When prompted to sign into an iTunes account, select ‘Create Account’.
Step 6: Fill out all of the initial information on the sign-up screen, it doesn’t need to be accurate apart from the email.
Step 8: Complete the rest of the form, the information you fill in doesn’t need to be legitimate.
Step 9: An email with a verification link will be sent to the email that you supplied.
Step 10: Download and sync your device, then the Angry Birds Go! will install on your device!
Just like that, you now also have an iTunes account which you can use to download and install apps before they hit the United States (and other) App Stores. You can follow the same procedure to create App Store Account of any other country you like.
Source : Thanks to Redmond Pie