8Jun/110
IPv6 day
As it is IPv6, there are a few things you will want to try. Of course, there is IPv6 itself but also any kind of teredo implementation for cross IP stack connectivity.
On your older XP machine:
netsh interface ipv6 install
netsh interface ipv6 set teredo client
On your Win7 machine:
nothing, it is there already!
On your ubuntu:
sudo apt-get install miredo
and voila you are ready to get connected and use the latest technologies. For testing any of that remember that most IPv4 command will work with IPv6 but may require some -6 option or use their IPv6 equivalent such qs ping6.
Then I would head to http://www.sixxs.net/misc/coolstuff/ for a bunch of cool stuff to try when on IPv6.
KitKatNeko