From the Dev+Mocha blog (routecafe.com) there's a post showing off an API to let your PHP scripts interface with the Bing.com site from Microsoft.

Well, since the opening of bing.com I've been playing with the API and some of the options it provides. Certainly I was getting annoyed since I had to rebuild each of my queries if I wanted something so I search for a library that could do this for me which I couldn't find and I ended up writing my own.

His API allows for a fluent interface to interact with Bing and grab the results from a search. The example given searches the site for "gimp" and returns the first ten values in an XML format. You can download the API here.