Anaglyphs are used to provide a stereoscopic or 3-D effect to an otherwise 2-D display. The idea is to trick the eyes in to thinking that the image is 3-D by offsetting the red and blue/green/cyan bands just enough to cause the depth effect. The result when viewed with special anaglyph glasses is an image that appears to be in 3-D. Download the full file from here.
Use the overview tool in Reader:
These images can be produced out of remote sensing software applications like ERDAS IMAGINE or manually like this and then import to the GeoPDF format so that anyone, anywhere can view them. This is an awesome application for the GeoPDF and I can't wait to hear form the field on how folks are using it.
Remember to use your Red and Blue anaglyph glasses.