The article writing & posting of them on any free article submission directory constitutes an important optimization process which is popularly known as article marketing these days. When quality articles are written on your website service or products & get published on free article directory it can drive huge traffic to your website faster.
Most of the instant approval article directories do not have high PR. So try to find good PR sites although it take time to approve your article.
Two auto-approve we use in our services that I haven't seen so far in the thread are - http://www.articlepros.com/ - PR 3 & sometimes http://infoinazip.com/ PR 1 as a backup We use loads more than that See this post but they are the only other two auto approves we know of.
Just a word of caution with goarticles.com you can't use a free email address when you sign up - that means you can't use email providers like yahoo and gmail. I guess they got tired of spammers submitting articles.
Thanks for the list. As long as these article sites aren't blacklisted and aren't viewed as poor link farms, these probably won't hurt.
You can also use the following PR 4 Directory sites http://www.2006cigr.org http://www.a1webdirectory.org http://www.a2zwebindex.com http://www.ab.poznan-online.com http://www.abc-directory.com http://www.acoon.com http://www.admcity.com/search/ http://www.adosinda.com http://www.adverts.gr/grsearch/pages/ http://www.agaccess.com http://www.allshops.com http://www.amidalla.com http://www.amray.com http://www.annasinkovska.com/fashion-directory/ http://www.apteka.tarnow.info http://www.arakne-links.com