pagerank

Is it possible to set an entire block region to "nofollow" for the purpose of pagerank sculpting? For example, take the use of a tagadelic tag cloud block on a website. If I wanted all those links to be nofollow automatically, how would I do that?

I'm curious what everyone is for pagerank sculpting overall. There doesn't seem to be a clear, straightforward way to add nofollow attributes to links in primary/secondary links to such pages as /contact et cetera... What's everyone doing?

-=- christopher