Heck, lots of search engines, and meta search engines, these days offer either (usually) to narrow the phrase with related phrases, or (sometimes) clustering.
Ask jeeves, Gigablast, Wisenut, Exalead, Looksmart (who are silly enough to put it at the bottom of the page where you won’t find it without scrolling), Altavista, and plenty of others.
The fact that Google doesn’t have it now, doesn’t mean nobody does, or even that it’s a rare and unique feature.