http://www.freenet6.net
Freenet6 server delivers IPv6 connectivity for end stations using IPv6 over IPv4 tunnels. Computers connected to Internet can use this free service to get connected on the 6Bone. http://gogonet.gogo6.com
gogoNET the new IPv6 community and services, it provides Freenet6 connectivity.
http://playground.sun.com/pub/ipng/html
IP Next Generation (IPng) Working Group Home Page
http://www.6bone.net
6bone Home Page
http://www.6ren.net
6ren Home Page
http://ipng.ip6.fc.ul.pt
University of Lisbon Science Faculty IPv6 testbed (in Portuguese)
http://www.stardust.com/ipv6/index.htm
Technology channel on Startdust.com for IPv6
http://www.ipv6.ru
Russian National IPv6 Forum
http://www.eurescom. … 02/html/brochure.htm
European Institute for Research and Strategic Studies in Telecommunications
http://www.ipv6forum.com
A world-wide consortium of leading Internet vendors, Research & Education Networks.
http://hs247.com
IPv6 News & Links

Also, most of the sites on our IPv6 accessible list are also reachable via IPv4.