Something that's really interesting, just unfolding: the release by traditional media companies of no-fee API access to their content. The term "API" means different things to different people, but in this context it generally means, "throw me an HTTP GET, and you'll get a sliver of my content" in machine readable format, usually XML or JSON. Generally the HTTP query must include a key, easily obtainable from the API provider, so that usage can be monitored. As a software developer, you can take that sliver of content and present it more or less anyway you like: plot New York Times restaurant reviews on a map, or show top technology stories from NPR in a blog sidebar, or do an information visualization of stories from the Guardian. Think of an API as exposing content with a web service without all that mucking around with something like SOAP. As a consumer, you can take advantage of some nifty apps that other hackers have put together.
Frederic Lardinois and other columnists at ReadWriteWeb have been tracking these developments closely. Of the current API offerings, that of the Times appears to be the most full-featured and sophisticated, especially the controlled ontology that the Times calls facets. The Guardian is just getting started, but it has an interesting list of partners in its Application Gallery. On my current project, I've had the privilege of an insider's view of the API from National Public Radio. I especially like the Query Generator, which step by step takes you through the assembly of a query and understanding the results.