Another cool tool from Google. With Google trends, you can see the search volume of a given keyword over time.

I tried using the search keyword "christmas gift" as I expect to see an increase in searches for this keyword during December. True enough, with the graph shown by google trends, the peak searches for the keyword "christmas gift" was Dec 2004 and Dec 2005.

The nice thing about google trends is google search for important news about the keyword which explains the sudden increase in search volume.

Try it out, search for "red sox" and you'll see a peak when they won the world series last 2004. Or "nba championship" and see the sudden rush of search volume during the championship.