Updated G2 Network Map
I updated the G2 Network Map. It now contains data from February 2009 to January 2012.
In total the crawler has collected 2.9 million unique hub IP addresses and 105 million unique leaf IP addresses.
The code I wrote for creating the map is published on github at IPv4 Heatmap source code. If you have a large collection of IP addresses that you want to visualize then let me know and I can help you out.