I've signed up for a Chictopia account and given the sight the once over, but I'm not sure how active I'll be on there if at all. I know people who like it more than lookbook.nu, but so far to me it seams like the myspace to lookbook's facebook -- i.e.: more confusing with features you don't need and too many people just dicking around.
Yes there are a couple features on it that I like that aren't on lookbook.nu (as there were on myspace), but so far I'm not too impressed. We'll see.