I found an interesting site not long ago called YouWriteOn. You can upload novel excerpts or short stories and from what I understand your excerpt is then sent out to random people who read and rate it. It seems less intensive than Critters (which I also joined and it just seemed too much for me; it feels like it's more for people who have loads of time) so that may appeal to some people.
It's worth a look!
It's worth a look!