What's the best way to approach a zip code proximity search on a location field type? I currently have a partner content type with a location field that I'm plotting on an OpenStreetMap.

I'd like to be able to enter a zip code, search against the location field for a radius of 10 miles, and find the closest partners to the entered zip code. The results could be displayed in a list, but could also be cool to zoom the map to the zip code being searched.

Anyone ever done anything like this with a location field?