Sex can work. There's a chemical in the guy's semen that can help to soften the cervix and induce some contractions. Also, if you have an orgasm they trigger uterine contractions and if you're close they could be enough to actually get things going. And if you're really desperate you can try castor oil. That's another thing that can help, but only if you're really close anyway. It will help empty your bowels out allowing the baby's head to drop some and press against the cervix more, hopefully helping to get you dilating.

And that's not all BS. It came from the childbirth class we went to when I was pregnant with Noah.