I need to list a bunch of addresses of homes and property. I would like to allow the user to input their zipcode and list the matches by the closest to farthest.

This way they can enter a cental point and get all matches in a certain radius.

Does ayone know of a program or method that this can be accomplished. I need to add it to an existing program, so I need something simple that wont take up too much server resources. My isp limits me to 10% cpu useage.

Any help would be apreciated.

How about this? scriptsearch.com/cgi-bin/jump.cgi?ID=4509

We did something similar years ago but the details are a little vague now. From what I remember, there are some data lists that correlate the zip code to a longitude - latitude value. From there it is fairly simple math to figure out what zip codes fall within that range. I remember we might have spent an hour in Google looking for the right db . Maybe try "longitude latitude zip codes" in a search?

Google Maps can geocode a zip code to latitude and longitude. I haven't tried running the same query by the Google API geocoder, but it should work. The expensive part of the transaction is doing the math to find the latitude and longitude intersections of matches within the specified radius.

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Fergus Gibson
realestatewebmasters.com

the math to figure out the distance between two points on a sphere (Mother Earth) is called the haversine function. I wrote a program that uses Google API geocoder to get the lat and long, then run it through the haversine function to get the distance in miles.

here's an example... dealer locator