Level Up to IPv6 with Ubuntu 10.10 on Comcast (Linux.com)

It seems that Hurricane Electric is the way to go for many people world-wide, because Hurricane has deployed a robust 6to4 tunnel server infrastructure in data centres around the world. See http://www.theregister.co.uk/2009/09/10/ipv6_traffic_surge/ - Hurricane is credited with part of a big traffic surge in IPv6 in mid 2009, by improving the quality of IPv6 connectivity quite dramatically.

OpenWRT also seems like a good option for many people as it supports a lot of different hardware, and it has some optional config GUIs these days. Unfortunately, Tomato firmware (which has nice QoS support) doesn't yet do IPv6. DD-WRT supports IPv6 but its freeness is questionable (http://en.wikipedia.org/wiki/DD-WRT#Controversy) and I had major problems with some versions even with IPv4.

Web hosting also needs to go IPv6 of course - takeup is not that wide, but http://www.fix6.net/ipv6-webhosting/ has a list.