Fyodor’s Nmap presentation during DEFCON 16 is now available in video form on insecure.org. Fyodor waited to release the video until Nmap version 4.75 was released, since the presentation goes over many of the new features in Nmap.
Two cool new features are the open port frequency options, and integration of the Zenmap GUI. Zenmap gives you the ability to visually map detected nodes in concentric circles based on network hops. For more information, check out the Zenmap Topology man page.