In his book, "The Moral Landscape" Sam Harris argues that you can in fact get "an ought from an is".
The split between facts and values is an illusion.
He challenges the assumption that science has nothing to say about objective morality, which he defines as our thinking about the well-being of conscious creatures.
Personally I found his book to be compelling; all the arguments against it that I have read so far are based on misunderstandings of his thesis.
I hve quoted Harris a couple of times when he said to his critics that he didn't want to be wrong any longer than necessary. In that spirit he has offered $10,000 to anybody who can refute the central argument of his book in 1000 words or less. The best attempt will receive $1000 even if it fails in it's purpose. A reader of his blog has since offered to double these prizes.
There is a debate on YouTube on the subject between Harris and Bill Craig who is at his vacuous best. Anybody who follows Craig's example is unlikely to earn 2 cents.
Here is Harris' lecture on the topic "Who Says Science has Nothing to Say About Morality" delivered at the Univesity of Oxford in April 2011.