In the blogs: Density map tutorial - Prototype, Google Maps API and the HeatMapAPI

http://feeds.dzone.com/~r/dzone/frontpage/~3/336202086/density_map_tutorialprototype_google_maps_api_and.html

A tutorial on how to create a density map with Prototype, the Google Maps API and the HeatMap API. The final product is a density map of liquor licenses in Milwaukee, WI.

Density overlays on top of Google Maps would be very cool! I hope I can find some time to experiment with this in the near future.