Squidoo, the site in itself already has a high
PR. It's 7. So if you build lenses(which are very similar to blogs) on Squidoo, you will feed off this high
PR. That's why it's very easy to get a high ranking in the search engine's for your lenses very fast. of course, they need to targeted on the right keywords and optimized, etc etc. but that's another whole thing in itself.
i think that if you had a very well set and optimized lens that was getting high amounts of traffic and was up for a while, your lens itself will build it's own
PR as well. but why worry about that when you can feed off Squidoo's
PR? you'd be better off making a bunch of targeted lenses and getting those ranked than putting all your effort into getting one single lens a high
PR.