This exists! ive seen it! I just lost the link. Somewhere out there there is a search engine that searches only blogs that allow follow in their comments. If anyone knows what im talking about, please post it here! thanks.
Yes these is but it doesn't work very well. I have lost the link myself but I used it yesterday looking for blogs to add to our "Do Follow List." Here is what I discovered. The navigation is real bad... The results are filled with "No Follow blogs" and it listed multiple pages from the same blog. They say that they have 815 blogs listed, but that more like 815 pages. If you would like a free comprehensive "Do Follow List" go here http://tucsonseosolutions.com/dofollowlistoflists. The list is updated weekly. Yesterday we removed 10 blogs for inactivity. So that leaves 280 blogs covering 25 categories.