I found a link to this site recently, and it offers some extremely useful tools for SEO'ers and webmasters.
Here's the link to the free SEO tools.
The following tools are offered:
1. Top Ten Analysis SEO Tool
For a search phrase, finds the top 10 results (and your URL) in Google, and for each of those sites, finds Yahoo rank, MSN rank, number of pages indexed, backlinks (page/domain/.edu), alexa traffic rank, allinanchor rank, age of the domain (whois), age of the domain (wayback machine), a count of the search phrase on each page, and a link to find related pages in google.
2. Backlink & Anchor Text Tool
Knowing who is linking to you and what link text they're using is one of the most important aspects in Search Engine Optimization. This tool checks your backlinks (only showing one backlink per URL that links to you) and shows the link text used to link to you. It takes a while for this SEO tool to run, but when it finishes, you've got a great report. This is a 2 part internet marketing tool. When the first part finishes, you can get a summary – often the summary is more useful SEO information.
3. C Class Backlink Analyzer Tool
Type in a URL and get a report that analyzes C Class backlinks, as well as creation dates of those sites.
4. Common Backlinks Tool
Type in up to 10 domains. We will find the backlinks for each domain, and then show the external domains that link to at least two of the sites you entered. These can be great sites to get links from.
5. Sitemap Tool
This tool will spider your site (up to 1000 URL's) and create a sitemap in ROR format.
6. Top Competitor Tool
This tool shows the top domains for a particular keyword in Google, Yahoo, and MSN.
7. Strongest Subpages Tool
This tool will find 30 of the strongest subpages of the domain entered, and will show how many other sites are linking to those pages.
8. Forward Link Title Tag Tool
Type in a URL and our tool will spider that site and show you the first ~500 links out from that site.
9. Internal Link Title Tag Tool
This tool spiders a URL and displays the title tags of up to 500 internal pages.
10. Internal and External Link Title Tag Tool
Enter in a URL and this tool will check your title tags, and the title tags of who that site links to.
11. Age of top 100 Websites with Backlinks Tool
Enter in a keyword phrase and we'll check the age of the top 100 sites as well as their backlinks.
12. Deep Link Ratio Analysis
This tool was created to analyze top 10 sites deep link ratio.
13. Cool Cache Tool
Enter in a URL and this tool will check that page, and all links off of that page to see when each page was last cached. Will also show if any pages aren't getting cached.
14. Down and Dirty Backlink Check Tool
Enter in a url and you'll get backlinks numbers in Yahoo, MSN, Google, Yahoo Linkdomain, Altavista, GigaBlast, HotBot, Teoma, & WiseNut.
15. Search Combination Tool
This tool will generate all possible combinations of two seperate lists of search phrases.
16. Keyword Density Analysis Tool
Enter in a page URL and this tool will tell you the keyword density of all the phrases on the page.
17. Spider Viewer
Enter in a page URL and see pages as search engines might see them.