>There's also this http://geocoder.ibegin.com/downloads.php
>
>US zip codes with longitudes and latitudes

Thank you, this is useful.

I have a class that calculates the distance based on two sets of coordinates. However, I am still curious to know how they do it to calculate so fast that x number of records correspond to a 50 km radius, from a specific location, taking from a 10,000 records table.