I haven't found anything that helps much. I bought some low sugar protein powder and I'll mix about 1 1/2 scoops in a water bottle and drink some of it every little bit, that seems to keep it from growling for a little bit. I also take some psyllium husk and put it in water and drink that, which will help for a little bit too (it only has about 15 calories so it helps with filling you up without all the extra stuff).
I've heard from a few people that if you have a lot of acid in your stomach it can make the growling worse, I tried tums which didn't really help but I've been thinking about getting some Prilosec and seeing if that helps.
Now if your stomach is growling and it's more of the digestive type noises, try taking some acidophilus, that will help take a lot of those noises away.