Ziki is another social network that has been making waves lately - primarily because the first 10,000 Ziki users get their name sponsored in Google, Yahoo and MSN for free. Ziki is loosely defined as a social network and I think it focuses more as a personal content aggregator while allowing you to promote your work and skills.
Personally, I think Ziki is spreading itself too thin - personal content aggregator, social network and psuedo-professional network; why not focus on just one? Ziki's moto is "be visible" and that it does. It's another way to get your name out there and interact with people and companies. Be sure to check out this redeeming Ziki post before coming to any final decisions.