Here's a fun website with practical applications. At citymelt.com, one can choose any of the 25 criteria "to find a place that is right for you", based on population/demographics, education, and weather. "Over 50,000 villages, towns, and cities available for your own personal analysis. Select county or state level data for your expanded research project."
Creator Stephen Traino notes that he will soon update the site with American Community Survey data when the new 2007 data for smaller places comes out in early December.
It's a bit quirky in that it seems to work best when picks just one criterion at a time. However, if you get too many hits, you can narrow the search by moving another "slider".