Check out Hittail, it's free!

[diamondseo]

You should take a look at hittail.com. It is a free analytics software, you just add a snippet of code to the end of your page and it will let you know where all of your visitors come from and which keywords they use to get to your site. It even offers suggestions on what to do with the keyword info you receive. (I do not own hittail.com, I just think it's an outstanding product - and free!)