A
fairly informative dissection and analysis of
Google Maps and how it does its magic. It's pretty interesting; unlike GMail (the other example of an impressive DHTML-based interface from Google), Maps doesn't use XMLRPC, but instead just fetches tiles in JavaScript and uses a hidden frame to communicate with the server, and the browser's inbuilt XSLT engine to parse the result. Which all makes for some very impressive hack value.