I stumbled across a link source so unbelievable today that I had to check it a dozen times to be sure. However, it appears that certain blog sections at Amazon, though moderated, do allow for inclusion of anchor text and external links without nofollow.
Check out pages like:
Amazon is “syndicating” feeds from the authors (or in some cases affiliated parties) of the products. Thus, if you or your organization has a product on Amazon, you too can create this “feed” and get direct links from Amazon’s pages. Note that many of these not only rank highly in the search results but have high PageRank as well.
This is truly an excellent way to leverage Amazon for SEO value.