Algorithm for heat map?

Question

I have a list of values each with latitude and longitude. I\'m looking to create a translucent heatmap image to overlay on Google Maps. I know there are server side and flash

Answer 1

I have tried to solve this in javascript using the canvas element, here is my current result:

http://gist.github.com/346165

I have to fix the gaussian filter and the color mapping, because it doesn't give good results currently.