At Google I/O 2009, we had the opportunity to meet many of our favorite developers in the Sandbox and Office Hours, and deliver several advanced talks on geo topics. Check out the description of those sessions below (originally posted on the Google Code blog), or jump straight to the embedded player and watch them yourself.

Mano Marks and Pamela Fox started with a grab bag session covering the vast spectrum of Geo APIs, discussing touring and HTML 5 in KML, the Sketchup Ruby API (with an awesome physics demo), driving directions (did you know you can solve the Traveling Salesman Problem in Javascript?), desktop AIR applications, reverse geocoding, user location, and monetization using the Maps Ad Unit and GoogleBar. Pamela finished by sneak previewing an upcoming feature in the Flash API: 3d perspective view.

In the session on performance tips for Maps API mashups, Marcelo Camelo announced Google Maps API v3, a latency-oriented rewrite of our popular JS Maps API. Also see Susannah Raub's more in-depth talk about Maps API v3. Then Pamela gave advice on how to load many markers (by using a lightweight marker class, clustering, or rendering a clickable tile layer) and on how to load many polys (by using a lightweight poly class, simplifying, encoding, or rendering tiles). Sascha Aickin, an engineer at Redfin, showed how they were able to display 500 housing results on their real estate search site by creating the "SuperMarker" class.

Mano and Keith presented various ways of hosting geo data on Google infrastructure: Google Base API, Google App Engine, and the just-released Google Maps data API. Jeffrey Sambells showed how ConnectorLocal used the API (and their own custom PHP wrapper) for storing user data.

On the same day as announcing better integration between the Google Earth and Google Maps JS APIs, Roman Nurik presented on advanced Earth API topics, and released a utility library for making that advanced stuff simple.