NetzSinn Address2Coordinates
By Bernhard Woehrlin
Custom Fields
Address to Coordinates allows you to assign several location fields, like street, city, zip code, or country. When a form is submitted, it will concatenate (combine) these fields and send them to the Google API, which will return the latitude and longitude, which will also be stored in custom fields.
Storing location data rather than querying on each visit will keep your number of calls down now...