I've heard of a few people doing the following (but not done myself, so I could be completely wrong)...get domain, 301 to high PR domain (Google, YouTube), wait for Google to cache the page, take off the 301, the domain still appears to have the high PR (and it appears in the index), sell quickly before page is re-cahced without 301 to high PR site.
Anyone with a modicum of common sense will see the scam. It's also easy to spot fake PR by checking back links. If you do this and can flog the domain to a newb, that makes you a c*nt. Don't do it!