All of the streets in the lower 48 United States: an image of 26 million individual road segments. No other features (such as outlines or geographic features) have been added to this image, however they emerge as roads avoid mountains, and sparse areas convey low population. The pace of progress is seen in the midwest where suburban areas are punctuated by square blocks of area that are still farm land.
This began as an example I created for a student in the fall of 2006, and I just recently got a chance to document it properly. Alaska and Hawaii were initially left out for simplicity's sake, but I felt guilty because of the sad emails received from zipdecode visitors. Unfortunately, the two states don't "work" because there aren't enough roads to outline their shape, so I left them out permanently. More technical details can be found here.
