Got a question regarding overlays and timelines in Google Earth (or possibly other KML-friendly clients).

I have data for every minute of the day for a given day that represents a numeric value for various areas on the map, and I want to display that data in a manner that looks basically like a weather radar map. So, for each minute, I basically have a big list of lat/lon bounding boxes, each of which has an associated numeric value; the display would involve drawing a polygon over the bounded area, and the polygon's color would depend on that numeric value.

I can see many ways of doing this for a single moment in time; either build a PNG with something like ImageMagick for the entire map area and overlay the bitmap, or draw the polygons directly on the map... the question, though, is how I can set this up so a time range can be selected by the user, and all the overlays which fit within that time range will all be displayed. And it has to be as responsive as possible, so efficiency is key.

It would be possible to pre-render lots and lots of PNG files, one for each time slice, for example; or would it be better to use polygons, or ... ?

Finally - is Google Earth the best client for this? Or would I maybe be better off with something else?

Thanks!!