This is a very interesting map of the IPv4 address space. Following image shows a visualization of BGP routing data taken from the Routeviews project. Here, 1-dimensional IPv4 address space is mapped into a 2-dimensional image using a 12th order This means that CIDR netblocks always appear as squares or rectangles in the image.
Each pixel in the original 4096 x 4096 image represents a single /24 network containing up to 256 hosts. The pixel color shows the size of the route advertisement covering that space ranging from /8 (purple) to /32 (red). Black represents space without a route and grey indicates reserved space.
You can order this map as a full size poster from project home page. I'm going to ask some one to get this cool map in our data center monitoring facility :D Note that most large corporations and government holds large IPv4 address space. I guess with the IPv6 we don't have to worry about allocation problem as it is a much larger address space that allows greater flexibility in assigning addresses.
=> Visit original project page : MAPS OF ROUTVIEWS BGP SNAPSHOTS [measurement-factory.com]