Create embeddable geo widget for third party websites -- 3

I have a website that is a "locator" type website for a particular industry. I use php, mysql and the haversine formula to sort results on my site using lat and lon coordinates. I need an embeddable widget that third party site owners can put on their site by easily copying and pasting a small snippet of code, that will allow their site visitors to input their location and view all of the [business] listings while still on the third party site. All of the data is held on my servers in MYSQL databases, and any type of information or data that you will need for the project will be at your fingertips.