Custom nationwide Google term-specific search map by zipcode & proximity script

I have a GoDaddy site which I designed and maintain using Website Tonight. I need a script written that will show Google Map results SPECIFIC to within a 50 mile radius of the IP address or city that the search is coming from and make that map viewable on my "Karaoke Bars In Your Area" map page when the customer clicks on the listing in search results that will take them to my map page. In order to get people to my map page from anywhere, I need google (or ?) to recognize that I am offering that customer's specific map for that specific customer ANYWHERE IN THE US. Maybe by tagging the IP address or something? (I have no clue). I'm not really sure if any of this is possible. But, I would like to show up on any search page throughout the country when people type in "Karaoke Bars in ???".