Google Code Blog: A proposal to extend the DNS protocol
By Daniel Miessler on February 2nd, 2010: Tagged as Technology
Our proposed DNS protocol extension lets recursive DNS resolvers include part of your IP address in the request sent to authoritative nameservers. Only the first three octets, or top 24 bits, are sent providing enough information to the authoritative nameserver to determine your network location, without affecting your privacy.
Sounds neat.