Photo courtesy of iStockphoto, Image# 6405862
IPv6 will soon be the standard for IP addresses on the internet. There are services (sites) that are now connected to the IPv6 network but inaccessible from the current IPv4 cloud. ISPs, unfortunately, do not yet provide full, native IPv6 connectivity to residential users. However, you can still access the IPv6 network by tunneling.
Setting up your Debian-based Linux, such as Ubuntu, to do IPv6 tunneling is not that complicated but it is not as easy as doing it on the Mac. To set it up, I refer you to this tutorial. Once you get it to run, explore the wonderful world of IPv6 beyond the dancing turtle, of course. :)