I've heard that just being on your hands and knees is supposed to help. Some people say to kind of rock your belly side to side. It's just a good position for freeing up space and encouraging movement. I've also read other moms claim they stood on their head. I can't stand on my head when I am NOT pregnant - much less during. Some doctors and chiropractors are skilled in techniques of turning babies - you may want to ask around as you get closer.
If your baby doesn't turn, have you asked your doctor if they are even open to the idea of a vaginal breech birth? Our third flipped to breech while I was in the hospital in labor (I had excess amniotic fluid and he had room to flip!) My doctor took a sonogram - while I was in labor - and measured the baby's chest, shoulders, and head. He looked to see where the cord was. This was 38 weeks, his head was actually smaller then his shoulders and since I had already two big babies vaginally my doctor was comfortable doing a breech vaginal birth. He left the choice up to my husband and I.
My doctor has experience delivering breech babies. The largest reason breech vaginal is considered unsafe is because many doctors don't know HOW. If they do, it's actually much safer and less traumatic for the baby then a c-section. There is a lot of misunderstanding with this. Many people have been made to believe breech is unsafe - on it's own it's not. You can have a healthy breech birth, if your doctor knows what he's doing.
We went into the OR just in case, I started pushing at 9:59PM and had my son at 10:01PM. :)
Since you mentioned none of your others were like this - it may be something to discuss? Though, take it from me - with a baby that flipped TO breech while I was in labor.. being 30 weeks you still have plenty of time for him to turn.
Good luck!