The Pew Internet and American Life Project has just issued a new report (PDF) on Wikipedia. According to the report, 36% of American adults consult Wikipedia. One of the more interesting aspects of the report is the amount of traffic to Wikipedia that's driven from search engines. The report cites Hitwise data that showed "over 70% of the visits to Wikipedia in the week ending March 17 came from search engines." This success must be one of the reasons that Wikipedia has announced they plan to launch a search engine.
Link via Micropersuasion.