It sure beats instant coffee. A major change to Google's results page has created an intense interest in interfaces that provide immediate feedback. Google Instant, which updates search results as you type, inspired YouTube Instant, which many developers have emulated using a number of different APIs.
Did you think the search engine wars were over, and Google won? New kid on the block Blekko, currently in closed private beta, urges you to reconsider. Once out, it's bound to become the favorite of search refiners, with the results likely made available as an API.
Once the mouthpiece and aggregator of the blogosphere, Technorati lost its luster long ago. And now it's lost its API, too. The developer page promises a new API but also makes one thing clear: the old one is gone.