Good Gear Guide
In Pictures: 8 cool heat maps that help visualise ...
Trulia: Local Real Estate Maps
Real estate heat maps cull data from a variety of sources. In the image here, you can see a visual representation of crime by geographic region to help determine where you want to live.
That data is pulled from SpotCrime.com and CrimeReports.com. For natural hazards, data comes from agencies such as the Federal Emergency Management Agency (FEMA), the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Department of Agriculture Forest Service. This year, Trulia added data for home and rental property prices, too.
In Pictures: 8 cool heat maps that help visualise Big Data