Use the Google Places API to pre fill your address forms. Its also a great way to virtually eliminate bad addresses. Simply start typing and a dropdown suggests addresses that match what you have typed so far. It works on any table in your database.
Taken from the Google Places web page: The Place Autocomplete service is a web service that returns place predictions in response to an HTTP request. The request specifies a textual search string and optional geographic bounds. The service can be used to provide autocomplete functionality for text-based geographic searches, by returning places such as businesses, addresses and points of interest as a user types.
Taken from the Google Places developer website:
The Place Autocomplete service can match on full words as well as substrings. Applications can therefore send queries as the user types, to provide on-the-fly place predictions.
The returned predictions are designed to be presented to the user to aid them in selecting the desired place. You can send a Place Details request for more information about any of the places which are returned.