Sizeasy is a Ruby on Rails web application that helps you compare the sizes of different items (for example: TOM BIHN bags) with 3D, Front, Side, and Top views.
From the Sizeasy Web site: “Sizeasy allows you to compare dimensions of items you find described on the web often. Many online stores show the dimensions of items like Product Dimensions: 192 x 45 x 32mm. Although useful this doesn’t give us a feel for the real size of the item that we would get going into a high street store. Sizeasy allows you to take this size information and see it drawn out to scale next to everyday items so you get a real feel for its size.”
A Sizeasy user has already posted a size comparison of the Empire Builder Vs. the Zephyr Vs. the Size 4 Brain Cell Vs. the Small Packing Cube. See it here.