I was at the SEO Meetup yesterday and shot my mouth off that there is a database of all google ceneroids for cities... aparently while google does let you download their cities csv from adwords its not just a list of centeroids and cities so heres my tool to keep good on my comment. It lets you geocode a city and then get distance of an address from the centeroid. It will be interesting to see if the lat/long coordinates match up to either of these datasets:

• Official US geonames [gov] http://geonames.usgs.gov/domestic/download_data.htm
• Maxmind GeoIP http://www.maxmind.com/en/worldcities

And if you want to know where the best post on local check out:
Local Search Ranking Factors http://www.davidmihm.com/local-search-ranking-factors.shtml

---

This tool is super simple to use:
1st put in the city name + state
2ed press calculate to see lat/long of the city
The results are shown at the bottom of the map

if you want the real distance from the centeroid then enter a 2ed street address and it will tell you how far it is from the center of town (according to google)