I did this one up last night while drawing up some 200dpi 2200x1600 grid paper of various types (grid, staggered grid, hex, vertical hex so far) in The GIMP. Because I used a certain coordinate as the "pilot" hex and this hex was in the same location on both hexsheets, the lands and grooves in the vertical and horizontal hexes made this neat looking pattern of hexagonal interference.

This is a small PNG image linking to the full-sized true-colour BMP (as Windows XP won't accept the PNG or a grayscale BMP as the desktop background, yay Microsoft), so right-click and Save Link As to your My Pictures folder if you're using Windows and want to give it a whirl.