title: Magento, add a custom attribute to a customer address
body: <p>I'm looking for a way to add a drop down for a customer's address (during registration, editing, checkout, etc..) that indicates whether or not it is a Residential or Business address. I have spent hours going through tutorials but they are all out of date or poorly written. I have read 6 different ones telling me how to do the same thing 6 different ways. Can someone outline a simple process that you need to do in order to add a custom attribute to an address? I'm on Magento 1.6</p>