Google AdWords: Free Keyword Tool External
Google’s free AdWords tool: “Keyword Tool External” shows everyone’s SEO dream — which keywords and phrases they’d like to optimize for. There are a few ways to analyze these results — and they’re discussed through this article in comparison to other major keyword tools.
Overture search inventory
Overture hasn’t been updated since January 2007, and has excessive timeouts. Regarding their accuracy, their data is highly lacking — relying on their data can certainly be costly. When a competitor relies on this data it can be most beneficial to you — since you’ll see many webmasters optimizing for keywords that just aren’t searched as much as they’ve been in the past.
Wordtracker
Wordtracker is “better” than Overture but still has many inaccuracies. I had searched for “SEO” and it turned up saying that there were 37 searches per day for “blackhat seo expert” (approx. 46 searches per day on Google — according to SEOBook’s estimates). I’m currently ranked number 1 for that term on Google. I then waited a few days and my referrer tracking has shown no visitors from that key term. So, Google’s Keyword Tool External shows that there is “no data”. Read more »
This is kind of a disgusting thing for a .edu site to do — but they’re doing it. From 
Google has made something just awesome. You can now analyze data like never before with 
. That means you can then optimize for them before there is a large amount of competition. 
The Looooooooooonnnnngg ping list is at the last paragraph (if you don’t care to read about the explanations of it, and/or view the short ‘n’ simple list of pinging places).