At the Developer Tutorials blog mentions, a new offering from Yahoo! is making it simple to "spice up" the results for your site when someone searches for it - Yahoo! Searchmonkey. It's a PHP-based platform for creating an application that's returned inline with the search results.
Rasmus Lerdorf has an example of the potential output for a search returning a restaurant's name, links to its menu/wine list, reviews and a link to make a reservation.