I like Channel Frederator RAW a lot. I have been waiting for a social network geared towards 2D animation and character design like this. I can learn a lot from pro-designers and animators already in RAW. I'm just trying to participate as much as I can. Someone mentioned contests too...I'll have to look into that and participate :)
This is the best networking site I've been a part of so far. I love talking about animation and posting up my work for fellow animators to see. This place also presents a great opportunity for those of us that are still in school and are looking for an in to the industry. It's refreshing and 10 times better than deviant art.
My only complaint is that the 'add friends' thingy pops up at the topmost part of the screen, but the page doesn't scroll up to let you know it's there! Took me two days to figger out why I couldn't add no friends. Other than that, Guy Like!