Sam Harris is here offering a substantial amount of money to anyone who can show a flaw in the philosophy of 'The Moral Landscape' in 1000 word or less, or at least the best attempt.
http://www.samharris.org/blog/item/the-moral-landscape-challenge1
Up to $20,000 is on offer, although that's only if you change his mind. Whilst we know that this is very difficult, note how few people offer large sums of money for the privelage of being disproven.
In case anyone does win, I will remind you that this site is created and maintained by people who work at MIRI and CFAR, which rely on outside donations, and with whom I am not affiliated.
Note: Is this misplaced in Discussion? I imagine that it could be easily overlooked in an open thread by the sorts of people who would be able to use this information well?
Could someone provide a quote or two showing that Sam disagrees with any of the above? Steel-manning only a little, I believe Harris' goal isn't to find the One True Definition of morality, but to get rid of some useless folk concepts in favor of a more useful concept for scientific investigation and political collaboration. He antecedently thinks improving everyone's mental health is a worthy goal, so he pins the word 'morality' to that goal to make morality-talk humanly useful. Quoting him (emphasis added):
I think this view is more sophisticated than is usually recognized. Though it's definitely true he doesn't do a lot to make that clear, if so.