One could play for hours with Google Trends (trends.google.com). Not only does it show the spikes and slopes of search volume across time since the beginning of 2004, but it also lists the current top ten regions, cities and languages for each search. You can search for multiple keywords, comma-separated, and see colored lines for each. The results are usually more interesting than revealing. Such as:

• Searches for Ronaldo and Beckham both spiked in 2005 at the last World Cup.
• Searches for John Paul and Ratzinger peaked one after the other in early 2005 when the former died and the latter succeeded him as pope.
• Searches for Linux and Microsoft have both gone down, the former slightly more than the latter.
• Searches for Red Hat, SUSE and Ubuntu show declines for the first two and a steady rise for the third. Add Linux and find that Ubuntu has almost overtaken Linux in search volume. Does the rise in Ubuntu account for the decline in Linux searches? They seem somewhat reciprocal, but who knows?

What's more surprising are the top ten regions, cities and languages for each. Some results for Linux:

• Russia is the top region, closely followed by India and the Czech Republic. The US is not among the top ten.
• Beijing is the top city, followed by Tokyo and San Francisco, which is the only US city. The rest, in order, are Milan, Frankfurt, Augusta (Italy), Paris, Amsterdam, Madrid and London.
• Russian is the top language, followed by German, Japanese, Italian, Chinese, Polish, Finnish, Portuguese, English and Swedish.

Some results for Ubuntu:

• Norway is the top region, followed by Italy and Russia. The US is not on the list.
• Milan is the top city, followed by San Francisco and Augusta (Italy). The rest are Helsinki, Madrid, Paris, Santiago (Chile), Frankfurt, Zurich and Mexico City.
• Italian is the top language, followed by Finnish, Swedish, Russian, French, Spanish, German, Polish, English and Portuguese.

Google's qualification: “Google Trends aims to provide insights into broad search patterns. Several approximations are used when computing your results. Please keep this in mind when using it.”

Also keep in mind that these were results on May 13, 2008. Try them when you read this to see how they change. Having used Google Trends for a while now, I can assure you the answer is: a lot.