As a Charlotte SEO , I often get asked questions about various SEO tools that are available.
Here are a couple of free ones that I have found quite usesful:
Multiple Data Center Google Search Tool - Google is comprised of a lot of different data centers. Different data centers can be running
different algorithms, therefore producing different results. If you want to get a consensus of where your site ranks for a certain keyword
across a sampling of different DC's, this is a great tool to use!
SEO for Firefox - This is a plugin for the Firefox web browser. It was created by the author of SEOBook.com, Aaron Wall. It's great at
giving you basic data every SEO needs to know while you're in the process of browsing!
On-Site Factors Tool - This is a great tool for analyzing things like keyword density and checking the relevancy of your description and
title tags to that of your content.
Duplicate Content Checker - This is a great tool for getting a detailed comparison of two different URLs. Breaks the data down very
nicely so you can differentiate between code and content.