You can also try evening primrose oil, and squats (:
Nipple stimulation, or pumping, can be very effective in inducing labour ! You should discuss it with your midwife or ob first, but mine actually recommended it as a natural method of inducing labour (: You have to stimulate for quite awhile each day for it to be effective, but it releases oxytocin which is the hormone that will start labour ! Since you are past your due date, I'd say go for it ! Congrats and good luck (:
I've heard eating pineapple, walking, yoga, and a yoga ball helps for some people.