From the site
Google Zeitgeist - Search patterns, trends, and surprises according to Google
For both breaking news and obscure information alike, people around the world search on Google at www.google.com. With a bit of analysis, this flurry of searches often exposes interesting trends, patterns, and surprises.
On a monthly, weekly, and sometimes daily basis, this Google Zeitgeist page will be updated to reflect lists, graphs, and other tidbits of information related to Google user search behavior.
While not updated often, this site has some neat statistics and graphs. And the archives should eventually be quite useful to students.
Last seen at http://www.google.com/press/zeitgeist.html