Display size comparison chart?

Try DisplayWars.com It will allow you to visually see the difference between screens of different sizes and aspect ratios. Only downside is that you can only compare two at a time. Here's an example (difference between a 4:3 13" display and a 16:9 15" display):

Not side-by-side, but instead overlaid, but very comprehensive:

• http://en.wikipedia.org/wiki/Display_size

  "Diagram comparing various typical screen sizes by width, height, diagonal, area and aspect ratio [color-coded]." -- Includes A4 (8" x 11"), A3 (11" x 17") paper designators for comparison.

• http://en.wikipedia.org/wiki/Display_resolution

  "This chart shows the most common display resolutions, with the color of each resolution type indicating the display ratio..." -- Includes designators like CGA, WUXGA, HD1080.