Gary Sieling has a new post to his site about scraping Google Maps data with a combination of PHP and some simple Javascript. It makes use of callbacks and timers to get the data already returned from their API.

Google Maps provides several useful APIs for accessing data: a geocoding API to convert addresses to latitude and longitude, a search API to provide locations matching a term, and a details API for retrieving location metadata. For many mapping tasks it is valuable to get a large list of locations (restaurants, churches, etc) – since this is valuable, Google places a rate limiter on the information, and encourages caching query results.

He includes the code (both front- and back-end) that you'll need to make the system work. It makes a request to the Google Maps API as usual but then adds a listener with a callback. This takes the latitude/longitude data and runs a "get details" method to get more information. The result is then POSTed to PHP and written out to a file.