Here is what I need done:
There is a Wordpress plugin that allows you to put geo-tags on posts (ie. addresses). It's called Geo Mashup.
There is an addon (Geo Mashup Search) to that plugin that generates a search widget through which you can search for posts within a radius of a zip code. That addon allows you to specify a few categories to restrict your search to... For example, you can display a dropdown of specific categories and people can choose to search for posts WITHIN a category of their choice that are near a zip code.
Now - for my site, this is pointless, because the categories are locations (states, counties, cities etc...). Instead, I have a custom taxonomy with 4 terms in it that represent different types of businesses. I want to tweak the search addon to allow visitors to choose a taxonomy term and only search for posts within that taxonomy term.
I spoke with the plugin developer and he told me that I'll need two things:
1. A customized [url removed, login to view] template that creates a dropdown menu with terms from your desired taxonomy. This would be a file you can add to your theme.
2. Filters to add the selected taxonomy term to the geo search query.
You can save time by hard coding the taxonomy you want to use, but this means that if you want to use a different taxonomy on another site, you'll have to edit the code.
That's all... Oh, and I want this done fast.