I heard a podcast recently on Jimmy Moore's site dealing specifically with sweeteners. It was said that the only really safe sugar substitute was Stevia, but that even then one must read the label and make sure that there are not other indesireable elements included. I went to two different stores and only found one that looked OK - SweetLeaf. I tried it in some plain Greek yougurt last night and it tasted fine. I can't post links yet, but the interview was called "The Truth about Sweeteners" and the interviewee was Dr. David Getoff.