in the eyes of google - no follow equates to NO LINK LOVE.
Matt Cutts said it himself on two occasions that Ive seen on youtube.
on the other hand, msn and yahoo don't share that algorithm.
To be honest thou, I don't trouble myself to get ranked on MSN or yahoo.
I focus on google and the others come around.
So I give you the 7 commandments of backlinking
1. Get yourself do follow backlinks
2. Get backlinks from a VARIETY of sources
3. Use the anchor text for the keyword you are targeting - 90%
4. We rank PAGES and POSTS not websites
5. Leak and don't flood backlinks to your pages or posts
6. That being said, you should aim some backlinks to your main domain on a regular basis.
7. Get backlinks from both 0 to 5 PR sites.
Be well and good luck in your internet marketing endeavors.
If you have any questions - hit me up