[UPHPU] databases for sale

[John]

> Does anyone know of a place that sells databases? I'm specifically
> looking for a database of mileage data. (Point A to Point B = x miles)
>
> TIA
> Timothy

Timothy, I had a client that needed/wanted to setup a store locator type
of system.  And in my research the only way to do that, and also to find
milage between two spots is to have the Lat/Lon of the start and end
points.  That said, you would need to have a database of Lat/Lon coords. 
But since very few people know their own Lat/Lon, you will find it tough
to work by that means.  So the solution is to use Zip codes.  Not just
zips, but a database with zipcodes and associated lat/lon.  The math is
past me, having to deal with the curvature of the earth, and the fact that
a zip code covers a large area, not just a pin point on the earth.  So you
would need to use acos, cos, tan and other math functions to calculate the
correct distances.  I really did spent some time looking into this because
I wanted my customer to have as accurate data as we could get without
spending hugh amounts.

There are many companies that sell zip code databases.  Some are even
free.  Some use free data from census reports, and some not only compile
it, but guarantee accuracy, because the Post Office is changing the
coverage of zipcodes and adding and subtracting them each month (they are
in charge of zip codes), and once you do buy a db, you can compare those
results to the usps.com website.  There are also a few that offer the PHP
programming (usually as a PHP class), which you can use within your own
code to get the results.

The place I bought mine from was (http://www.zipcodedownload.com/).  They
have several products to choose from.

Thanks
John