Angus, it's bad form to post a follow-up question without replying to Steve's response on this earlier thread.
To repeat Steve's response, equally applicable here:
Steve Luke wrote:The first question would be to see if it is legal. Check out the Google terms and conditions and see if you are allowed to use their system this way. And in your research you might also look to see if they have an API you can use to interface with their application - making your work a whole lot easier.
There are no new questions, but there may be new answers.