Last week, Google introduced a new spam filter that enables users to customize searches by providing the option to block unhelpful web sites from appearing in future results. After looking at a link and clicking the back button, the option to "block all example.com results" appears under the search result summary. Logging into a Google account will save preferences about which web sites to block, and will omit any results from that site in future Google searches. The search engine will indicate how many sites are blocked from each search at the top and bottom of the results page, and sites can be added or removed to the block list in the account settings. The feature provides the ability to personally customize searches, but Google is not using this information to universally modify search results at this time. Learn more from the Official Google Blog here, on Lifehacker here, and MSNBC here.