Don't tell anyone, but the Semantic Web really is cool.
5.9.1. The Hack
The first step is to find the GMap object in memory, which is the key to the Google Maps object structure. Every page that shows a Google Map (under the official API) must have a line that looks like this:
var map = new GMap(document.getElementById("map"));
But what about the overlay content? That HTML exists within an anonymous function passed to the GEvent.addListener method. That function is placed in the _e_ _click array and is already compiled. The only way to get at that content is to call the function. The trick is to capture the call to openInfoWindowHtml by copying the existing method at GMarker.prototype.openInfoWindowHtml and replacing it with our own function, which captures the HTML argument when requested, and otherwise calls the original backed-up method.
Finally, the RSS is produced by iterating through the overlays array, grabbing the x and y from the point, executing call( ) on the _e_ _click function, and wrapping it up within an RSS item element. The geocoded RSS is then written to a new window.
5.9.2. The Code