I have wondered for years why Yahoo haven't attempted to use del.icio.us as a back-end for some sort of search engine. I don't think it requires any great leap

I have wondered for years why Yahoo haven't attempted to use del.icio.us as a back-end for some sort of search engine. I don't think it requires any great leap of faith that searching for a combination of keywords that numerous people have already tagged the page with indicates it's relevant. Hell, even improving the searching in del.icio.us would be helpful - basic ability to sort by number of people who have saved a page would be incredibly useful, for example.