I caught Just How Powerful Is Wikipedia? over on Seth Finkelstein's Infothought blog. Kelli Shaver whipped up a PHP script to check a list of search terms in Google to see if a Wikipedia link appeared on the first page of results. They ran the Long Top 1000 list from Wordtracker through the script first. The Long Top 1000 list contains the top thousand most searched for keywords over the past 130 days taken from a database of about 300 million searches. Unfortunately, the list has a ton of adult-related search terms, and Wordtracker’s “remove offensive content” filter is more or less useless.
Even so, they found that an amazing 50.2% of the top 1000 searches had a Wikipedia result on the first page. (That’s 502 out of 1000 for the math challenged.)