To access Zeitgeist it takes more than number crunching with Google. However, from time to time I look at Google figures – in case I missed something - at
Search patterns, trends, and surprises according to Google
It is not really "according to Google", but according to what (mostly) people look for with help of Google. And I admit, often I find, I missed something (and more often, I think, I do not miss what I have missed).
You can look at Google's Zeitgeist this by weeks, months and years (back to 2001) and now actual, Google has published their "2005 Year-End Google Zeitgeist" . Besides
Google News - Top Searches in 2005
Froogle - Top Searches in 2005
Google.com - Top Gainers of 2005
7. Sky News
8. World of Warcraft
9. Green Day
10. Leonardo da Vinci
Google Zeitgeist looks at World Affairs, Nature, Movies, Celebrities and Phenomena , here!