Great Post…..

I would like to add one more: “Using NoFollow in Blog Comments” (If you are not using WordPress – as NoFollow in comments on WordPress blogs is default)

I also like to add little note on NOFOLLOW: “Nofollow is method to explain a link to tell search engines “I can’t or don’t give your word for this link.” In Google, nofollow links don’t pass PageRank and don’t pass anchortext [*].”

And have Questions Also:
1> If Using Nofollow Is So Beneficial Why Are None Of The big Sites Doing This: (SITES LIKE BBC.COM, REGISTER.COM, ECONSULTANCY.COM, etc, etc)

2> What if ? Take Example

There is one page of blog/site having 100 comments, that means 100 NOFOLLOW Links for just commenting + other nofollow links like you said (RSS FEED, HOME PAGE, etc etc)

Doesn’t too many NOFOLLOW LINKS hurt your page ?

3> Is NOFOLLOW tags still work for increasing the page rank?

Regards,
Kamal Patel