IPv6

From DreamHost

DreamHost is close to adding support for IPv6 addresses to any domain hosted here. IPv6 offers a few advantages, not the least of which is the enormous pool of addresses available (in comparison to the legacy IPv4 network). Because of this large available address pool, DreamHost will initially be offering unique IPv6 IPs for free with any domain.

However, IPv6 isn't without its limitations. The first of which is minimal support by Internet Service Providers. Because of this lack of support, most people will need to use what's known as a "Tunnel Broker" to connect their IPv4 home network with the IPv6-enabled internet. A company called Hurricane Electric offers such a free service at http://tunnelbroker.net/.

Some more information can be found on Wikipedia about the subject: http://en.wikipedia.org/wiki/Ipv6