Are there any more dofollow blogs/ sites with really high page rank like Squidoo.com and Hubpages and Gather.com?
There are many but I personally like the following 2 (apart from 3 you spoke of already)
Bukisa.com and eHow.com are no follow
associatedcontent doesn't allow promotion.
Wordpress are blogspot are great as long as you maintain them for long and add a quality unique content and bit of link building to the blogs itself. Even if you update them at least twice a month, that works. As long as they look natural and not not made for link building, they work well. Blogspot is easier to handle, you just need to change the header so that "report abuse" is removed and your blog will be great forever.
same goes with weebly and blogsome, as long as you maintain them for long and Google likes them for being natural and handled by a genuine user.
Most of the sites listed in the Free Blog Hosts thread are dofollow.
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