i have a friend who has been anorexic for about 5 years, and has been hospitalised for a long time in the middle of that. even now, she won't go over 7st at all! and she's quite tall, so it's not a good look for her, it's horrible to see how it's affected her over the years...
however...and this isn't me saying that these sites are a good thing, b/c believe me i hate them to pieces... but, i once began having serious problems with food, over exercising etc, and i stumbled across one of these sites whilst looking for the lowest calorie food possible...
well, whilst it didn't stop me straight away, a few visits to this site did put me off the path i was walking along quite a bit, and i didn't stop straight away but over time i realised that i did not want this life that these girls were telling me i did. seeing their aims and aspirations (thinspirations...) it was like a shock back to reality, to what i was doing to myself, and to my mum in particular...
i just think as bad as they are, a lot of the time if someone is already deep in the throws of anorexia then these sites won't affect them so much either way. again, i'm not saying for definite that it wouldn't help someone along that path. but from friends and acquaintances and my own experience, i've found it to be a shocking insight to the life that you may be starting to lead, and can actually work to scare people away with the harsh realities of a full-blown eating disorder.
now i have a distinct feeling i've probably contradicted myself to hell along the way...!

ideally these sites wouldn't exist, but then as i think a previous poster mentioned, they do offer some form of support for those who feel they are the only ones, completely alone...
lerato.xxx