Yahoo! Term extraction API

Yahoo! now offers a term extraction API call for content analysis. You provide Yahoo! with some text and Yahoo! returns what it determines are significant words or phrases in order of significance.

Using this API call a developer could pass a weblog post to Yahoo! and receive an ordered list of suggested tags for that post. Combine the results with Technorati’s top tags API call and you can choose to include only the most popular contextual responses.