You can always use http://courtneytuttle.com/blogs-that-follow/ That's probably the largest list that I've seen. You will find that many of these blogs re-enable nofollow if they get overwhelmed by spammers.
The site here has a great search engine that will wind relevant blog posts with dofollow comment links and comment luv!
Here is great tool that can do it for free: http://www.fastblogfinder.com/ . Just write a blog post about it and you can get the full version for free. Please note down that I am no way affiliated with it.
Can you explain that please. I have been trying the free version but it's not producing results that would make me thinking about a purchase. Writing an article on my marketing blog would not be a problem in exchange for the full version but I had a look at their website and could not find anything that confirms your statement.
its a combo of german / english sites that it will search through. I found enough english sites for my needs!
The EASIEST way to find Do-Follow blogs is to search for "you comment, I follow" in Google WITH QUOTATIONS. That'll keep you going until you die.