blekko has its own 4 billion page crawl and index, with lots of fairly unique advanced search features hidden away in our slashtags. I realized recently that we've done a terrible job of communicating our advanced search features to anyone outside the company. So I wrote this tutorial, aimed at advanced searchers. Tell me what you think!
/date is also a cool blekko feature! Searching for /tags also gives a nice list of a bunch of slashtags that can be used to nudge your results in many different directions!... If you're into web programming for example, you could search for something like "JSON /api" and get a totally different and valuable set of results!