The question for me is does nofollow really prevent PR leakage? Since I'll probably be dealing with PR 0~1, I'll need to build similar pages with an embedded keyword and compare one page with 100 links with nofollow on all of them versus another page with 100 links that doesn't use nofollow(?) Note that the PR of the page itself won't change. The difference we want to see is the PR of the pages this page links to. If one page gets a link from a non-nofollow 100 link page, then say it gets 0.01PR transferred. Another page with 99 nofollows and 1 clean link should get 0.02PR, so ranks higher in the SERP. As contrast, say I have another page that gets a nofollow link. That should get 0.00 PR and rank the lowest.
So how many pages do I need for this test? Say 2 pages with 50 links on each page. The links go to big sites like cnn.com (so I don't have to build crap pages). Page 1 will use nofollow on all of its links. Page 2 will not use nofollow. Now we also build page A that gets linked from Page 1 using a clean link, and page B that gets linked from page 2. Finally, we have page C that gets linked from page 1 with a nofollow on the link. As for content, title, meta tags, pages A, B, C should be nearly identical.
The keyword for this test is testxzrelnofollow seo4funf5s. The linkfarm pages does not contain keywords, just links to major sites.
Nofollow Page This page is populated by miscellaneous outbound links. PR/number of Incoming links to this page should be exactly identical to the next page.