Free SEO Tools - from Aaron Wall
Free SEO Tools
There are many free and pay for type of SEO Tools available online. Today I thought I would point out to you some of the Free SEO Tools available on Aaron Wall’s website SEO Book. He has over 20 free tools for search engine optimization. Many you can also download the source. Let’s ignore that Aaron counts a little different then most people (he has #4 on there twice). 
Here is a summary of a few of his SEO tools:
Spider Test Tool - shows the page size, source code, meta tags, page title, textual copy of the page, keyword breakdown by density (including 2 and 3 word phrases), number of words, number of unique words, and outbound links on a page. Check out Spider Test Tool here.
Search Engine Saturation Tool - helps you compare how many pages you have in the search indexs compared against competing sites. Check out the Search Engine Saturation Tool here.
Google Suggest Tool - shows frequently search for phrases starting with the words and letters in your query. Check out the Google Suggest Tool here.
Link Harvester - allows you to deeply query the Yahoo! database and gives a good amount of link details.
* web based
* really fast
* makes sorting out duplicate links from the same site easy, which allows you to quickly and deeply query the Yahoo! backlink database.
* does not give anchor text
* gives breakdowns of .edu links and number of C block IP addresses, etc.
Check out the Link Harvester Tool here.
Be sure to check out his website for some more of his very helpful SEO Tools.