Embryonic stem cells are not obtained by harvesting the products of an abortion. They are obtained from embryos that are the result of IVF or Somatic Cell Nuclear Transfer and other cloning methods.
In the case of humans, the embryos must be at least at the 5 day or 250 cell stage in order to harvest sufficiently differentiated cells. Otherwise, the potential is twinning rather than stem cell lines.
http://www.healthnewsdigest.com/news/hlth_stemcell-17.html
http://www.time.com/time/health/article/0,8599,167245,00.html
(Really, there's so much information available from Google, this site and Medline that there is no excuse for posting when you're so poorly informed.)
If you had read the threads between MGHinTn and me you would have noticed that we were discussing the ethics of stem cells not the science. Showing off your knowledge about stem cells is not pertinent to the discussion I was have with MG.