The title of that post was misleading as the post was about resources and not tools, I'm frustrated by the number of posts out there now that "list" free learning resources. (there are far better lists out there)
They could have written the post with a different intention and focused on actual tools for self directed learning that uses the resources (that are interlinked) listed on that blog.
I haven't been able to find many; most of what I use I've had to develop on my own and extract from the biographies of well known autodidacts.
One of my current projects is to start writing up on my process and the intellectual tools I've developed for it, but, it is waiting on the completion of my web app before that gets going...
If you check out my Delicious bookmarks, you can find all of the web related resources I have and use. http://delicious.com/ixmatus
They could have written the post with a different intention and focused on actual tools for self directed learning that uses the resources (that are interlinked) listed on that blog.