Jessica at TownMe.com has sent me this amusing tool to mash up Google maps with Census data to rank city neighborhoods based on different factors - e.g. Yuppieness, cougars, baby mommas etc. You're able to see which neighborhoods are more concentrated with these different factors. Below is a the Yuppie Locator for San Francisco:
You can do a search for other major cities. They also rank the city with an index, on a scale from 0-100, for a certain factor. The index is located to the right of the map. If you click the 'read more' panel, you're able to see how they defined and described the index and exactly which pieces of census data they used.
UPDATE: Moments after posting this map, I visited The Map Scroll. Chachy has also featured this site... AND used San Francisco for his example. LOL... great minds think alike. I think Chachy may live out there... I only chose SF because the data map for Dayton was pretty boring...