Geocoordinates and database query (repost)

I would like the two functions below written in PHP and integrated in to a WordPress 3 site. 1. The site should use an api to translate location entries into geocoordinates and save them into the database. The provider used should be one that allows a minimum of 100,000 requests per day. 2. Given the new coordinates, the system should query the database to find the other entries that are most similar based on proximity and compatibility of route. I have written the logic and will share with the successful candidate. It involves a small number of calculations, and a database query.