“The Tom Bihn Large Cube is made expressly for the Aeronaut carryon (see review) but, at 13.5 x 13.5 x 4.25, it will fit in almost any bag. And it holds a lot. Here’s what I got in one cube: two pairs of medium-weight pants, one long-sleeved dress shirt, one heavy wool shirt/jacket, and one t-shirt. If you pack purposefully you can fill up every square centimeter of the cube.”
Read the entire post at One Bag, One World or check out the Large Packing Cube.