Christy,
It is called Extraamniotic Catheter Balloon, where a foleys catheter is inserteted above the internal cervical os (so just inside the cervix). It is blown up using normal saline, small amounts over a period of time. It is supposed to be a more gentle method of ripening the cervix. Often used for women who are having a VBAC. A definate favourite of my friendly doctor.
HTH