I've been using wire cubes from Target or Wal-mart or Meijers ever since I started. There are webshots pics of them in my first quilting space in 2004. The stash has quadrupled or more, but we've just kept adding the cubes! I'll add some new pictures one of these days.
I have a bolt core covered in a slippery fabric and use it to fold like it would be rolled on the bolt, then slip it out and fold over once. Nice rounded edge and very neat. And the fabric stores are happy to give you one.
If you look at the photos, you can also see some extra cube sides that I've slipped in to separate lengths of fabric from fat quarters in similar colors.
Oh--in my current space I also clip a doubled piece of batting at the top with a few bulldog clips. It serves as a display wall when needed, or flips up and away when not.
There aren't many organizational things I stay satisfied with, but this has been one of them!