[snoj]

Tonight I was looking up ways to get a list of zip codes within a radius of a given zip code. Because I dislike paying for things I can get for free, I finally found the 1990 US census database. You can find both the 1990 and 2000 data here. The 1990 set is easier to parse.

Now, on to the algorithm to obtain an area of zip codes!

[Jayman]

Oh my, I think you are going about this the hard way, my friend.

Why not just grab your information from an existing web service?

http://codebump.com/...codelookup.asmx

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GetZipCodesWithin
Returns a list of zip codes within a specified distance from a given zip code. Parameters: zip - 5 digit US zip code or Canadian postal code (M3H, M3H 6A7), distance - distance in miles.

You have to register for this one, but it is a free subscription. The only restriction is:

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50 miles maximum search radius,
distances rounded to nearest integer,
user-defined places are not supported

[Jayman]

Here is another one that is free.

http://teachatechie....es/ZipCode.asmx

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GetNearbyZipCodes
Returns a DataSet containing maximum of 250 zip codes and radius milage within a given radius of a zip code

[snoj]

Thanks for the linkage Jayman. However one of the reasons that I require my own solution is because this is for a subscription based website. Which many for free services frown upon.

[Jayman]

Ahh, now I understand. And here I thought I was going to make life a little easier for this project. Oh well, maybe next time.

[Programmist]

I would be secretly happy that I couldn't use the free web services because coding that algorithm sounds like fun.

[dreamseek]

Thanks! This post is quite useful for the ZIP code demographics site I'm working on. Appreciate the expertise in this forum.