This idea is sufficiently retro that it almost doesn't even qualify as new. After all, Yahoo started out as little more than a list of categories, from which users self-narrowed the search on the front-end, after which users could either browse, or search more specifically. It's seeing a resurgence lately, with a few "new" twists like tagging; as if tagging could still be considered novel; but anyway you look at it, you're
Too Late, Somebody Else is Already Doing That. E.g., take a comparative look at
accoona - News Search - "Net Neutrality" versus
Kosmix - US Politics - "Net Neutrality".
