Location - GMAP interactivity

Hello,

First of all, I do apologize if this is a duplicate. Please redirect me if it is.

I have a traditional setup of a "single" location CCK field in a node that is using GMAP for the latitude/longitude. We require that the GMAP update to the city when the Location fields for "city", "state", or "zip code" and "country" are updated.

I know that I can simply add a form_alter hook in a custom module for my node type and add the onblur event for the exact fields, but I would like to create a better - more dynamic - solution.

I assume that I should add settings to a macro, and I know I will have to make changes to the location.module as well. Can you give me pointers where to make the changes, your ideas and any things to watch out for. I wish to commit a patch as soon as I have some things working.