I just found this stuff at Google about publishing what they call "Subscribed Links" for your site which allows readers to give your results priority when they use Google.
I am hoping some clever plugin developer would be interested in creating a plugin that will create the file necessary for publishing such a "feed". It is very similar to a standard RSS feed but needs to have keyword information added to the feed. See http://www.google.com/coop/docs/subscribedlinks/tsv-webfeeds.html#rss
So, I figured you could take the WP feed, then extract tags and maybe title data to create the new feed needed for Subscribed Links. I don't know if that could be done independent of the tagging plugin that a person is using (I use SimpleTags).
So, here's a free idea if anyone wants to run with it. Please just let me know when it's available. :)
Message me if you want more info or to discuss.