Or...
You can Google intext:"this site uses KeywordLuv" or something like that and you'll find blogs which uses this WP plug-in. While this is not exatly a plug-in which removes the attribute nofollow, blog owners who uses this usually strips the nofollow thingy because KeywordLuv allows commenters to use their keywords as anchor tags.
Bloggers use this plug-in because they are encouraging people to leave comments on their blogs which adds content to their site. As a reward, that's where the nofolllow stripping comes.
Hope this is not confusing and I hope it helps.
Also, you can try searching for CommentLuv.
Good Luck!
And yeah! Got my first post! hehehe