To the people that say no-follow links are a waste of time. In what world do you live in? No one is going to give you a link on a PR3 and above with do follow links if you don't deserve it. Stop complaining, this site must have traffic, and you might recieve organic traffic from the link. No link is a waste, every link counts.
It's better to get comment links from blogs that moderate comments. It's too risky to leave comments on websites that allows spams, more harm than good.