I haven't used this, but I'm going to in a project this month.
I don't plan on buying their developer tools. I'm just going to get the zipcode database with the latitude and longitude. Once you have that calculating the distance between zipcodes is pretty simple.

You can find various links on this but here is one:

http://www.meridianworlddata.com/Distance-Calculation.asp




>Robert,
>
>Thanks for the link. I assume you have used this in VFP and are satisfied with the speed and the way it works?
>
>Thanks,
>
>Jerry
>
>
>>http://www.zipcodedownload.com/
>>
>>
>>>Is there a way to determine distance from a zip code?
>>>
>>>For example, we would like to point our customers to a dealer closest to them. We would like to have the customer enter in their zipcode and then we would like to display a list of dealers in their area, within 50 miles.
>>>
>>>Is there a calculation to use, such as: the first 3 digits of the zipcode will be a 50 mile radius and the first 4 digits will be a 25 mile radius and so on?
>>>
>>>Thanks,
>>>
>>>Jerry