Alternative search engine Blekko has launched a major update, called “Zorro,” which includes an expanded search index with integration of the slashtags, which have been the staple of the site.

On the new results pages, users will see sites that others have hand-picked to be included in one or more slashtags. So far, users have created over 100,000 of them. The company considers this a human site review element to the “war on spam.” The slashtags appear at the top of the search results, and for each site boosted by the slashtag, next to its URL.

“Millions of users and hundreds of millions of searches have given us insight into what is truly great quality content on the Web and what is poor quality spam,” said Blekko CEO Rich Skrenta. “This new version of blekko bakes in that intelligence in every search so the spam gets weeded out and the best content comes to the top in every search.”

In addition to that, search results will display sites’ logos. Blekko says this is so users can “quickly choose results from trusted brands that offer the best content.”

Though stumbling a bit in some months, Blekko has continued to grow since its launch. Compete has Blekko.com at 211k unique visitors in the U.S. last month, after launching last fall.

Finally, the Zorro update comes with a “new relevance model for ranking.” This includes “a ramped up adspam algorithm, identifying millions more pages on the Web that contain multiple ads and little content.” Such pages, Blekko says, have been permanently elminated from the index so they’ll never appear in search results.

Blekko is so confident in its search quality, it has also introduced a little game called 3 Engine Monte, which lets you enter a query and see three different sets of results. One comes from Blekko, and the others from Google and Bing. The user’s job is to pick which one they like best, and they think users are apt to pick Blekko fairly frequently, I’m assuming.

3 Engine Monte doesn’t appear to take into account various kinds of search results offered in the other engines through Universal search. For example, if I search for “mexican food” it doesn’t show me all of the local stuff and the images that Google actually shows me if I go to Google and perform the search. As far as the purse “ten blue links” type results, I’ll give Blekko credit for offering better ones (and Bing as well for that matter) in some instances that I tried.

Interestingly, it does show you which results in the competitors’ results that it has banned. The game can be accessed from the home page of Blekko.