This form and code do a Google Maps and Yahoo PlaceFinder API lookup and parses the resulting XML to extract the formatted address and latitude and longitude of the address.
May 2012 UPDATE: Google says this page is "Over query limit." but their limit is 25,000 queries per day and I have less than that on this page for years. I don't know why Google is limiting this page. I'm now using Yahoo instead of Google. It's easier and it's working.
NOTE: You must get your own AppID. Get it here