"couple your search terms with what Blekko calls “slashtags”—predetermined filters that limit your search to a particular set of websites. These can be those created by Blekko or user-generated. They can be topic specific, convey an opinion, eliminate spam, act as sorting mechanisms, or directly search another site.Since you can create your own slashtags, Blekko qualifies as a social search engine.
Blekko’s built-in slashtags include /people (limits to pages associated with individuals), /liberal, /conservative, /news, /politics, and many more. To sort results by date, combing search terms with the slashtag /date or date range with/dr=yyyy:yyyy (where yyyy represents the year). Third party slashtags include /amazon, /bing, /google, /twitter, and/youtube. Specific tags for /weather, /map, and /define are self explanatory.
Some of the Blekko-created slashtags work better than others. I’ve had very good luck with /blogs, /techblogs, and /forums, which effectively searches blog and forum sites, but results from /humor have been atrocious. Not only were they generally not funny, they were frequently in questionable taste. Some of Blekko’s slashtags are odd, such as the 88 websites identified as /lego. You can view all Blekko’s tags by entering /tags in the search box."
My biggest complaint about Blekko is its 404-like error message upon using the "wrong" kind of slashtag, that is, one that doesn't exist. Here's a typical error message followed by an invitation to create my own useless slashtag:
The slashtags you entered /"david and mattison" are not valid
Create your own slashtag '/"david'