There are a lot of posts where people say get free PR7,8... backlinks like the post about the j0omla forum and many others. Just to make it clear only the main page of the forum has PR 7 or 8. When you link to a subdomain no ---> no PR you will get, unless the page has a lot of content and very few posts are in there so yours get in the page with high pr. For sure, this kind are not impossible to get but very hard to find. Also through my personal experience if you want to get your xrumer or scapebox links indexed in a very short time. Find a website where g0ogle crawler's spiders check every 15 to 20 minutes. Now especially with google instant, where results from these websites appear as they are posted in goOgle .These are generally portals and there are many in wp. Make sure also if you find this kind, not to overuse them or you will get banned (ip) so make sure you connect through different browsers and also from different ips. Remember to clean your browser history and cookies to get this done.