Sophrosyne Stenvaag posts a defense of "unrealistic" avatars that is well worth reading, and I have to say I agree.
Yes, body image and what people do to themselves in RL is a serious issue. Models who look like they went straight from the concentration camp to makeup to runway are neither beautiful nor healthy.
But... this is SL, where we can do better. [Insert sound clip from The Six Million Dollar Man here.] Why should we settle for our RL selves, products of genes selected for scarcity in a world of abundance, our telomeres shortening like that ominous fuse crawling across the Mission: Impossible intro?
Head over to Sophtopia and, as Glenn Reynolds says on Instapundit, read the whole thing. (And some other things, too, while you're there.)