Google Trends is a fun new toy: search for a term, and it gives you a graph of that term's popularity over the past 2 years. It also gives you a listing of the top geographical origins for that search.
You can also combine several terms to see how they compare. To demonstrate, here's a visualization of the ongoing battle between "Rock" and "Music".
google.com/trends?q=rock%...
You'll notice that Rock crushes Music as easily as it crushes scissors. Also, this combination ranks Minneapolis in the top 10 cities worldwide, a result for which plurib.us readers are no doubt responsible.
[EDIT] As Brian points out, the graph demonstrates Rock getting thoroughly walloped by Music. Not only that, but Minneapolis has been knocked off the Top-10 list. Something here is not my strong suit: accuracy? timeliness? In any case, I'm led to believe that Google Trends exists only to mock me.