Maybe Dracula had it at least a little bit right: apparently blood really can keep you young, but only if it's your own. In the UK, the hottest new antiaging procedure is "S3" or Stimulated Self Serum skin therapy, which is a pretty alliterative euphemism for injecting your own blood into your face. Well, not your blood, exactly, but the clear serum that's left over once your red blood cells…