Yes why not. Actually most of the sites are turning themselves towards no follow links. Most of the high pr and quality blog, article, social book marking, forums and so on websites are now rewarding only no follow links why because they require high quality contents. High quality contents play an important role in this regard. No follow links are considerable by Google by some instinct and help the user to get traffic from those sites those who already have built numerous audience levels. So keep no follow sites within your database and retain your practice of posting those sites.