So i decided to experiment, using social networking etc sites as a way of implimenting back links to my domain and the results are interesting... a rise on page 1 from 8th to 3/4 (fluctuating) for my SERP "web design leeds"

see the sites i linked to at Web Design and Marketing Guru (for some reason when i input the domain name here it replaces it with my page title?)

BTW its worth going through these sites and adding in a few blog posts, making your profile as complete as possible whilst still trying to add weight to your target terms.

Im happy with the result. just need to re-design my portfolio to increase conversion!