Have you noticed the fancy new graphic in my side bar? (BTW, I didn't make the original, but I did make a graphic by combining all of the colors ) It's an idea that by removing the ”nofollow” tag on your blog that you can share a little link love. By removing this tag , you are allowing the comment authors and their blog to get a reciprocating link back to them.
I believe the original explanation for needing this tag was to reduce spam, and to stop link farms from being able to keep having high page rankings and search results. I don't get a lot of blog spam to begin with but this tag certainly hasn't stopped spam on my blog.
So I'm jumping on the band wagon. I'm hoping- as others have said- that this will encourage lurkers to de-lurk. You leave me a comment, and you get a link back to your blog from you comment. It's that simple. This will in turn boost you page ranking therefore making it easier for people to find you site via search engine.
Here are a few articles on the "Do Follow" or the "U Comment, I Follow" topic:
Prepare for more comment spam, not less
Hey Google, Follow Me: Giving More Link Love
U Comment - I Follow
Link generously - you will reap what you sow
Interview with a link spammer