The newest Search Engine in town Blekko has opened up for public searches, you no longer have to be a logged in user to search. However, there are features that Blekko offer where it would be of use to the searcher to register. In my Blekko Review I wrote about the beauty of Slashtags, marking spam, and more of the unique selling points that Blekko has to offer.
Though it is still in Beta development and some technicalities need to be addressed, (are you reading Blekko? Anphicle.org has been 301′ing to Anphicle.com for 4 months!), it is a step in the right direction for the Californian startup, and is exciting the search industry too.