Yes, a list of links would be a good start… Although in a situation like mine, where I have zip codes and area codes from all over the country, it could be a very, very long list.
A drop down list box or a slightly modified version of your category drop down list box filter might be another way to go…
If the user could start typing a zip code or area code in your existing category drop down and it would start filtering based on their input…
That would be nice or something along those lines.
For my application, which is helping people find how much corkage fees are based on their current location or where they will be going, any way for users to filter by zip code and or area code is a big plus.