K.O.
I have 6 kids. When I had my first one, they said to always put them on their tummies. When I had my 3rd one, they said to lay them on their sides. When I had my 4th one, they said to lay them on their back...which by the way caused him to have a flat head---but he grew out of it.
The thing about all this is....DO YOU WANT TO TAKE THE CHANCE? If a baby is going to die of SIDS, there is NOTHING YOU CAN DO TO STOP IT. You cannot sit by their beds and try to startle them out of it. Their heart just stops and usually can't be revived.
So, I guess my opinion is that you should just keep them on their backs until they are able to roll over on their own.
I just keep telling my kids that it is a miracle that they are all alive. :)