FLICKR is the ultimate Web 2.0 App – one of the first to implement tags, RSS feeds, and AJAX (Asynchronous JavaScript and XML); to offer APIs to third-party developers; to encourage mashups; and to incorporate groups or “lite” social networking into a tool previously viewed as family-centric.

But Flickr’s biggest lesson for enterprise IT is how it took an existing mainstream app – photo sharing – and changed the paradigm altogether.

Rather than copy existing “album” and “slide show” models to the Web, as early online photo sites such as Ofoto and Shutterfly did, Flickr started with a blank slate, treating all photos as part of one universal photo album that could be categorized, shared, and presented in infinite ways. It also lowered the bar for accessing content.

Although not part of Flickr’s initial launch in 2004, tagging has proved central to Flickr’s ability to scale and add value to an otherwise unsearchable universe of photos. Users can add keyword description tags when uploading photos, thereby creating a taxonomy that would have been impossible or cost-prohibitive to create centrally. Flickr also allows users to navigate via “tag clouds”, visual representations of photo-subject popularity.

Enterprises looking to expose end-users to troves of content should consider leveraging user-created taxonomies to aggregate and share that content. Not only does the approach facilitate collaboration, but much can be revealed about the company’s collective interests.