For those who might have missed it, the Blekko (http://blekko.com/ http://blekko.com/) search-engine already allows one to do this in a quite powerful way, and

For those who might have missed it, the Blekko (http://blekko.com/ http://blekko.com/) search-engine already allows one to do this in a quite powerful way, and Google's plans might have been a response to it. (the beauty of improvement through competition...)