Free Internet Marketing Tool Collection: Part One

I've been finding more and SEO / Internet marketing tools on sites these days, so just for fun I've decided to start a list. I've named this post "Part One" because I am sure there are PLENTY more out there, and I don't want to make this first post an exhaustive list. Here goes:

http://www.urltrends.com
Interesting trending idea upgrade for them to make some money.

http://www.linkhounds.com/link-harvester/
Linkhounds seems to be trying to create an all over linking resource site. Cool that their software is open-source. This requires some more looking in to.

http://www.digitalpoint.com/tools/keywords/
Keyword ranking trending. Requires free login, but nice charts.

http://www.marketleap.com/publinkpop/default.htm
Nice link popularity, search engine saturation and keyword ranking tools with many industry benchmarks.

http://www.submitexpress.com/tools.html
Really cool meta tag checker that shows keyword density and tag relevance to page content.

http://www.bruceclay.com/seo/tools.htm
One of the more in-depth keyword density and prominence tool I've seen. The free access link is near the bottom of the page.

If any of my thousands of readers knows of any more, please feel free to add them to the comments. :-)

Update: September 4th: The Big List of SEO Tools:
Ok, these guys at seocompany.ca seem to have the biggest list of all:
http://www.seocompany.ca/tool/18-toolbars.html