IPv6

DreamHost now allows customers to add 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.

Enable IPv6 for your domains
From the Dreamhost newsletter: "Just visit the “Manage Domains” section of your control panel and click the “Add IP” link by your domain to make the magic happen. This new address is tied to your hosting machine, but other services like email and MySQL are not yet supported. We also don’t (yet) support IPv6-only domains; you’ll need to have an IPv4 address on there too. [...] Luckily a device can be assigned IPv4 and IPv6 addresses simultaneously so you can do an “out with the old/in with the new” at the same time!"

Limitations
However, IPv6 isn't without its limitations. The first of which is minimal support by Internet Service Providers.

(is this information still valid?) 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/. Also, for non-US people, http://sixxs.net/ works well for tunnel based IPv6 connectivity (I use it Darkflib 10:55, 9 June 2011 (PDT) )