It’s the thing to say in the social networking world, isn’t there a service where I update my profile once and all the other profiles get updated?

AtomKeep claims to solve the problem.  They do support all the major social networkin or web 2.0 sites e.g. Linkedin, Facebook, MySpace, YouTube and more.

They are in Beta so sign up and try it out. I do put the disclaimer that I have not tired them out. If you do, do share your experience.