Its amazing but a lot of people I know don't even use Google trends. I had a CEO shake his head, "no" and look at me blankly and goes... "What is it?"
WOW..... http://www.Google.com/trends is your new best friend.
You should be in the habit of checking it every day or at least two times a week. I use it a lot to see what is trending on the web. You can use it to find out where a hot market is taking off. Google trends offers you a map and will show you where your search term is popping up the most. It will break it down by region and by city which is very useful.
You can use it to forecast where something is taking off. It should be used as a rough guide line but it is fairly accurate.
Check it out.