This is a Google Earth, time animated version of the U.S .ZIP map in my post from a couple of days ago. Based on Robert Kosara’s ZipScribble maps. 

The KML file contains 43,000 lines connecting every ZIP code in the country, TimeStamped in ascending numerical order.  

Just a slight warning: This is a very large and detailed time animation. It runs smoothly on my 3-year old PC (the little GIF above is from a real time capture), but may not work on some computers.

ZIP Scribble Map (USA) (650kB)

Viewing the File

• Hit the play button in the Time Control, top right of the screen, or just drag the slider left or right. 
• Expand the time span to increase the number of ZIP Codes displayed at any time.
• Deselect folders in the left sidepanel to alter the scope of the animation.
• Change the visualization to a cumulative animation by selecting clamp beginning of time window in the time option dialog  - accessed through the white clock icon to the left of the time slider.

and…

• The numbers shown under the Time Control are 5-digit ZIP codes without the leading zeros.
• States are different Colours. No significance in the choice of colour - it’s just for contrast with one another and the terrain.
• White lines indicate the sequence jumping a State boundary.

P.S.  for a different take on visualizing ZIPs,  check out Ben Fry’s  Java, zipdecode.