This 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 Hilbert curve, as inspired by xkcd. This means that CIDR netblocks always appear as squares or rectangles in the image.

Address blocks are labeled based on IANA's list of IPv4 allocations. Early recipients of large "class A" address blocks appear in the upper left, while the areas labeled Various Registries indicate allocations from the former "class B" and "class C" regions. Since the mid-1990's all address space allocations are now made through the Regional Internet Registries: RIPE, APNIC, ARIN, LACNIC, and AfriNIC.

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. Prefixes are rendered in order from largest to smallest so that larger (covering) prefixes can be seen underneath the smaller (more specific) announcements.

Visit the gallery to view additional types of maps and the Routeviews gallery for historical BGP data and animations.

source:
http://maps.measurement-factory.com/

this is a dump of information I came across in the interest of ad-free archival and credit to original work I have verbatim pasted this in my blog.
cheers