Monday, Google added some more data to help AdWords advertisers pick the best keywords for their campaigns. They have added "global trends," which basically means they are showing you the search volume for a particular keyword phrase, graphed over a 12 month period. You can view the keyword tool for free at https://adwords.google.com/select/KeywordToolExternal. After punching in a keyword phrase or two, you can click the "Get More Keywords" button, then when the page loads, select "Global search volume trends" from the "Show columns" drop down menu on the right side.
There is not much forum discussion on this addition, since most of the folks who discuss AdWords in the forums use more advanced keyword tools (I guess). But here is what I dug up; WebmasterWorld, Cre8asite Forums and DigitalPoint Forums. The main complaint is that they do not provide search volumes in numbers, without this or some sort of scale, it makes it hard for real pro users to use.