SEF ... The Search Engine Forums

Old post I know but it's getting read.

As for SEO tools there are a few, none more important that your own brain of course. As for SEO software/tools I use the following;

Web CEO Professional Unleashed.
The free version of Web CEO puts the full versions of IBP, SEO Elite and Web Position to shame and is fine for doing your own sites though to use it commercially you need to purchase the correct version. There are some very noticeable differences between the different versions least of all the general advice compared to engine specific optimization advice.

I also use the Google Ad Words external keyword tool for keyword research as Web CEO uses data from around 50 other search engines exclusive of Google so using both and cross referencing gives a clearer indication in regards to Google. I also like to use Googles Web Trends to fine tune keyword selection more-so when targeting specific locations.

Another great web based tool for keyword research is here [link]
It is basically Wordtracker and Google Trends combined, very useful especially for a free tool although I do prefer to just use the Google external keyword tool and Googles web trends myself.

The only tool I use is www.frelic.com
it allows to me to be informed when someone remove a backlink of mine.
It is a backlink checker, but it does not need a directory to work, so I can manage all kind of websites.