What are the best keyword research/analysis free tools that you know?

I would have to say google trends is one that has worked for me as well as a few others. Like google insights you will have to do a bit of research but it is well worth it when you see the out come of traffic from the keywords and your income increase. Hope I have helped. Thanks.

Watching this thread:)

None.

Honestly, I think just writing is preferable to anything else.

I use two different ones, but neither is free. Actually if you just want the keyword research tool part of it, it is free to use Market Samauri. But you have to pay if you want all the tools it offers.

The other one I use, which I prefer because it's hosted on their website so I can access it from anywhere online (it's not software you have to download to your computer), is Jaaxy keyword research tool. But it's $19 per month. In my opinion it's makes me WAY more money than what I pay for a monthly fee so it's worth it. They are offereing a $1 trial for a full week if you want to try it out for only $1, but they are only offering this on Feb 1st from noon-midnight. If you miss that deal, you always get 10 free searches for FREE to try it out anyway. But some of the data (like the competition data) is not shown in the 10 free search trial. Anyway, I've been very happy with Jaaxy. I use it mainly for my webpages I create over on Squidoo.

Jaaxy doesn't tell you the CPC for adwords, but Market Samurai does. So if you are looking for one to use for Google Adsense purposes, then I'd recommend Market Samurai.