Free Article Directories

In my last post about "Having Ideas to Blog About", I mentioned that free articles directories are a good starting point to have our own ideas, remember?
Ok, this works with me and might not work with others but in my opinion, free article directories are a good place to find topics because they have a wide range of categories where you can start looking for new ideas.
Well, I´ve been looking around, investigating, and I found some good quality articles in these directories:

http://www.articlesbase.com/

http://www.articlecircle.com/

http://highwire.stanford.edu/lists/freeart.dtl