Blekko , the stealth search engine startup co-founded by Rich Skrenta (of ODP fame), has recently launched a limited private beta . I've been able to give it a spin and can confirm, it feels like early days yet for the project but it does have its core metaphors and functions nailed down solidly. As close observers now know, the service allows users to use pre-set (or custom) "slashtags" to reduce a whole web search to a narrower slice of relevant websites.