Links from site with PR0 will do no harm to your site - Google does not penalise you for any sort of incoming links, as they are not necessarily under your control.
There are no such thing as pages with no pr. Every page has some pr. So there is no way they will kill some of your pr. Sure they won't raise it much but they won't be the cause of your loss of pr.
any link will help to some extent. the site in question may not have PR now but may have PR in the future also. so if you have a chance to get a link from a good site, get it
Google never penalizes you from link coming from a unranked Pr or a low PR site. Though depending on the quality you can benefit more or less from that link. If that link is from your niche you might get more link juice as compared to if you have the link coming from a non-niche site of yours.
Agreed.. even links that appear to be 0 PR will still help in little ways (and definitely won't hurt!).
its ok to use them, but I wouldn't bother. I look at it this way, they might become popular in the future and when you have tons of backlinks fromtons of low traffic sties, it can really add up
I agree with almost everyone here, link is a link, it will help SERPs i guess, plus who knows in a few month this site increases PR?
SEO wise, currently it is no profit and no loss for you from PR 0 site. But it's PR can increase in a few months time even possibly exceeding one with current PR 3, hence why it can be important to still act on some that have potential. But only if the potential is seen, it pays better to concentrate on higher PR sites since your time is a scarce resource which you have to allocate between alternative competing uses. Traffic aspect must also be taken into consideration since a PR 0 site or lower PR site can even sometimes give you more traffic than a higher PR site.
PR is one of the least important factors when placing a link, look at the sites backlinks, it's relevancy, the quality of its content and so on, things like that will help you a lot more, the PR we see is not relevant and added to which PR can be misleading, dropped domains or penalised sites which would do you no good from a link perspective could still show up as a PR8 in which case if you're paying for links (which you shouldn't be) then you're pretty much being robbed.
I agree with the above that PR is of little importance. That being said, I don't think having a link from a low ranking site is a bad thing. If all your links are on deep pages with a low rank, then you might be going down the wrong path, but a diversity of links from various pages is never bad. I would be more concerned with the content on that page, rather than the ranking of the page. Make sure the content is related to your site and clean.