You know what I want from search engines right now? Not clustering based on semantic identity of the keywords I'm searching for, which I am to understand is what clusty does, but merely classification of webpages as, e.g. "this is a forum post" vs. "this is official documentation" vs. "this is a commercial advertisement" so that I can check off some checkboxes to say I want one of them and not the others. Of those three, I'm sure there's been at least one time I definitely wanted each one of them and had my search results crowded with the other two.
If I'm just being dumb and there is an existing search engine that does this, I would love to hear it.