web application: the creation of an interactive map designed for GPS-enabled mobile devices

For my food/drink blog-index site [login to view URL], we want to develop a web application that has a heavy emphasis on geolocation services. Our main site uses WordPress to present blog posts, event calendars, and indexes of places to get good food and drink in California's Central Coast. I've also been creating some Google maps to present the index info spatially. The interactive map would integrate these features. Ideally, it will allow users to select whether they want info displayed on the map about the best cheese, coffee, and bread shops, for example, and would bring up all the relevant recommended businesses in a category and would center the map on the place where the mobile device (and/or desktop machine) is located. Users should also have the ability to add or remove items from their search so the map just displays the businesses for which they're searching. Would this be generated in PHP? We need to make sure it works on Apple devices so Flash is a no go.