Fix geolookup

I have 3 custom post types labeled (accommodation, restaurants & attractions). All posts in the custom post types have 2 custom fields that have longitude and latitude in them.

The previous developer started to setup so when you visit the single.php template for one of the custom post types it showed 4 posts from the other 2 custom posts types using the closest longitude and latitude.

I really need this working by Monday afternoon so please don't quote if you can't do it by then.