This package let your iPhone has an alternative 5 row Deutsch QWERTZ keyboard for iOS4.

There are three layouts now and you can choose them in the submenu of keyboard settings.
5Row: The special characters of first row are same as your computer keyboard.
5Row-CustomSymbol: The special characters of first row are which in common use.

After you install this package, please use Winterboad to apply the them.
Then, go to Settings > General > Keyboard > International Keyboards, Choose German (Germany) > 5Row-Deutsch.