Banking / Post redirection
If you are leaving Germany forever, you should close your bank account to avoid paying charges without using it.
Update: Jan 2014
To close your checking account, you can send an informal letter to your bank, including your name and address and details of your new bank account in order to transfer the remaining balance. Make sure that there are no outstanding direct debits or standing orders.
At the post office you can also redirect your mail to your new address abroad. Using this postal service (Nachsendeantrag), you can choose a time period of either 6 or 12 months. You should book this service at least five working days before moving.