I used to use Yahoo back when it was run out of a dorm room at Stanford, and still had a Stanford URL. Back then, Yahoo relied on volunteer labor to submit and categorize the growing numbers of URLs that made up a WWW that was at the time quite small. That's why Yahoo's recent acquisition of Flickr, a community-based photo sharing and indexing site, represents something of a return to the company's roots. Flickr hosts user-submitted photos, which are then tagged with descriptive metadata by community members and made available through the site's photo search engine. It's good stuff, and it represents a model that could be extended to multiple types of media besides photos.
Yahoo, knows that the Flickr model is flexible, especially the community-based content creation aspect, which is why they just launched a search site that's dedicated to indexing and making available works published via the Creative Commons license. Larry Lessig, one of CC's creators, helped Yahoo implement the new search, and he had this to say about it on his blog.