By the way these are all of my forums, so you can be sure that I'm ok with people coming in my forum for backlinks just as long as you don't SPAM
Most of the sites listed aren't known by the owners to be "dofollow". They will ban you or remove your comments if you try to drop backlinks. My forums you are free to do so because Im openly dofollow on my forums.
Hey there, feel free to add http://www.fourthfloormarketing.com to the list, my rather new internet marketing blog.
100 is not too many. You can never have enough. If you have many sites you need hundreds of websites to build backlinks off of
Greatly appreciate your sharing. I too have a list Do-Follow sites may be its useful to others. http://palatnikfactor.com/2008/09/12/list-of-over-100-do-follow-websites/