IPV4 HEATMAPS RELATED LINKS

Map of the Internet -- The IPv4 Space, 2006: This xkcd comic was the first time we saw someone use a Hilbert curve to represent IP address space, and was the inspiration for our own maps. It has a nice explanation of how the Hilbert curve works.
Hacker's Delight: This book, published by Addison-Wesley Professional, devotes an entire chapter to the Hilbert curve.
LANDER IPv4 Census: The LANDER project at ISI uses this technique to make maps of their ping-based IPv4 census data.
Characterizing Address Use Structure and Stability of Origin Advertisement in Inter-domain Routing: This 2005 tech report from Pennsylvania State University also uses a Hilbert curve (which they call a ``quad chart'') to draw pictures of BGP data.
IPMaps - BGP/Darknet Data Visualization With Google Maps: This web page puts BGP and darknet data inside the Google maps interface.
Stanislaw Skowronek has a program called xmap which can be found at the bottom of his NSA@home page.