A good conversion can only be achieved if the website is well constructed.
SEOguru.nl (Dutch) has an article in which Matt Cutts (Google spokesman) stated that you can't use nofollow for pagerank sculpting anymore.
The Dutch website http://www.seohandleiding.nl/google-strooit-met-kruimels.html has an article on the introduction of Google breadcrumbs.
I have a habit to analyse each website a visit. Especially since I have installed the SeoQuake toolbar (Firefox Plugin). The toolbar has a lot of usefull information that's updates each time you visit a page.