I own a ball winder and a swift, but I hate the fact that I pretty much have to let balls of yarn hang free when trying to wind a center pull yarn because the ball doesn't fit on the swift.
This morning I experimented with something - an empty bottle + a fat dowel. You stick the fat dowel through the center of the ball, then stick the down in the empty bottle. Set the yarn up in the winder and go. It works on the same idea as the ball winder except with a much smaller center rod thingy. I'll put up a picture soon. Now I'm off to the train station.