The Ultimate SEO Tools Checklist

It would be a good idea to have an ultimate Tools list, sorted by Various categories so that we can all find out what others are using, as well as new users have something to refer to as a starting point. If we get enough responses, this could become a very handy resource.

Please post the tools you use for the following SEO Activites. (Both free & Paid, Blackhat & Whitehat): Please try and stick to the format if possible, however feel free to add categories that I may have missed. You do not need to answer each category if you are not currently using anything for any of the following:

Finding Niches
Keyword Research
Tracking keyword Position over time
Checking ON-Site SEO
Creating one way Links
Finding Relevant Paid Link Partners
Finding Free Link Partners
Directory Submission
PPC Campaigns
Article Creator/Mixer
Article Subnission
Viral Marketing
RSS Feed Submitter
List Building & E-Mail Marketing
Competitive Analysis
Social Media:
Domain Acquisitions
Website Acquisitions
Campaign Measurement
Other SEO Tools

I will start off with Mine:

Finding Niches: None (Considering Discover Niches)
Keyword Research: Wordtracker, Market Samurai
Tracking keyword Position over time: N/A
Creating one way Links: Manual
Directory Submission: Manual
Article Creator/Mixer: Mass Article Creator
Article Subnission: Mass Article Submitter
RSS Feed Submitter: RSS Submitter
List Building & E-Mail Marketing: PHPList (I know its outdated but its free)
Competitive Analysis: Market Samurai
Social Media: Tube Blaster Pro, Tubeinator
Campaign Measurement: Google Analystics:
Other SEO Tools: Web CEO

Thank you brother

I use Internet Business Promotor mate and its ok, not the best tool on the market tho.

Tracking keyword Position over time: Market Samurai
Checking ON-Site SEO: IBP

Article Creator/Mixer: The BestSpinner
Creating one way Links: Xrumer, Senuke

Some good suggestions there. Especially interested in finding out what sort of tools people use for "Competitive Analysis" other than MS.

Just bumping it to see, if we can get some more ideas?