Forum OpenACS Q&A: Re: gps to zipcode query: postgres or postgresql + postgis or how?
I've come across Egnor's work before. In fact I am almost positive I found a link to it here, but I cannot find it now (I'm also getting some sort of error when I search for zip (but not when I search for zipcode)).
But uh, I wasn't sure how to make use of Egnor's work. My take was that it was more a work for Google to implement than one of us. It involves, if I understood it correctly, crawling the page for patterns that make up addresses, and then associating the 3D location of that address to that page.
So if your query is "show me the stores within 20 miles of here", there is no way that you or I can implement that, that has to be done at google. I believe.
As a smaller matter, he also acknowledged there was some work to be done on his address patterns, noting IIRC, that while Google lists three addresses on their contact form, his address parser only picked up one of them.