As someone knows Google update his Page rank, these days. If you control TOOLS ON SEO BLOG , for example you can see that the page rank of your profile on Blog.co.uk is ranked but some Blog home page not why? I think google considered Blog.co.uk as community and in community Home page ot ranked, only the profile page. Blog.co.uk opened a new page for us: made GUESTBOOK . When you sign in one Guestbok you generate 2 backlink for you: One backlink for Your Blog Home Page and one for Your Profile page. If you write others URL these will not valid ( not in function) . I think that that one is a good thing and if you pubblish that one many peoples go to sign for generate valid backlinks for blog.co.uk sites: I don't know if that one thing will valid for others bloggers ( that doesn't submitted with blog.co.uk...)