The United States Geological Survey (USGS) publishes data on recent earthquakes through various RSS feeds. I came across this recently when I thought I had felt an earthquake. This was a nice opportunity to do something with a heat map, I thought... So I made this mashup with Google Maps and the USGS data.
I used a nice heat map component from Michael VanDaniker, the Google Maps Flash API, the AS3 MarkerManager, and Cairngorm. Using the Cairngorm framework was probably a little overkill for a small project like this... but at least it's ready to go if I want to add more functionality.
As usual, you can view the source by right clicking on the app. Click here, or the image above to launch the map.