I can parse any document or web page and tell you what words exist in the content. I can tell you which words are most used or potentially meaningful in the content.
What I would like to have is more meaningful sets of key phrases and tag sets that are specific to certain topics and industries.
I would like to be able to sent a title of a page or blog entry to an API, then have it return several tag and key phrase sets that are relevant to run against the body of the page to see if they exist.
Then I could run a secondary comparison against various keywords I find in the body.
Make sense? Yeah geeky I know. Just sharing a thought, out loud!!
Seems like an API you could build upon Google Analytics and use the TargetingIdeaService. I will have to investigate other existing keyword tools out there that have an API.