Simple Geographic Data Sources for a Web App

Question

For a web app I'm working on, I need to know the lat/lon of about 300 US cities. I also need to know the lat/lon for every US zip code.

Does anyone know of a free source to get this information?

Answer 1

Freebase will likely be able to help you. Here is New York and it has Lat/Long.

The Wal-Mart Expansion video used Freebase to get it's data, and it sounds like you're doing something similar.

Answer 2

Take a look at Ben Fry's Zip Code Visualizer. This is part of his book Visualizing Data.

Answer 3

There is an online database at Geocoder.us. And a simple perl module (we added a soap service to this so we could simply access it from any language, and the longest part of the development process was downloading database (it's about 4 GB).) The geocoing database is available from the US census bureau, a good article on getting this setup can be found here.