The implications of this really jumped out at me. There are the obvious benefits - infertile/homosexual couples would be able to reproduce. It would also make possible "perfect" contraception - safely sterilize yourself knowing you can still have children.<p>On the other hand, this would completely undermine maternity/paternity testing (and thereby associated laws?). Anyone could unwittingly sire someones offspring by shaking their hand (imagine what crazed fans would do with this).<p>Anyone else have thoughts on this? I suppose while the promise of stemcell technology was always obviously revolutionary to me, this "What If?" just made its disruptive potential clear.<p>*edit: re-maternity/paternity laws, i wonder what legal precedents are set by people contesting responsibility on the grounds of having an identical twin.