SEO Keyword Tool to Find Trends

Keeping track of trends and the most popular search terms can be valuable from both an organic and paid search perspective. Having aggregated information on the most popular searches from sources such as Technorati: Popular, Flickr Hot Tags, Delicious Popular Tags, Lycos Top 50, AOL, Yahoo Buzz, Google Hot Trends, Amazon and more can be a great at-a-glance resource.

This is what the free Popular Searches site from SEOmoz offers. It provides the top 10 searches from all sources for the current day, and popular searches and tags aggregated for ease of viewing, all in one place. It also allows you to access the archives for the information by date. It can be helpful to follow trends and see what people are talking about.