When I installed FreeBSD onto my server it setup an IPv6 address, funky I thought although I'm never going to use it. Anyway my Mac is also built on BSD and it too has an IPv6 address. So I tried a normal ping but it only supports IPv4 so I tried typing ping6 and it worked! Cool!
So anyway I now have two computers talking to each other with IPv6.
electra:~ michaeldale$ ping6 -I en1 fe80::200:e8ff:fe6c:557b
PING6(56=40+8+8 bytes) fe80::211:24ff:fe2a:f1b3 --> fe80::200:e8ff:fe6c:557b
16 bytes from fe80::200:e8ff:fe6c:557b, icmp_seq=0 hlim=64 time=1.365 ms
16 bytes from fe80::200:e8ff:fe6c:557b, icmp_seq=1 hlim=64 time=1.338 ms
16 bytes from fe80::200:e8ff:fe6c:557b, icmp_seq=2 hlim=64 time=1.382 ms
16 bytes from fe80::200:e8ff:fe6c:557b, icmp_seq=3 hlim=64 time=2.111 ms
16 bytes from fe80::200:e8ff:fe6c:557b, icmp_seq=4 hlim=64 time=1.433 ms
16 bytes from fe80::200:e8ff:fe6c:557b, icmp_seq=5 hlim=64 time=1.379 ms
16 bytes from fe80::200:e8ff:fe6c:557b, icmp_seq=6 hlim=64 time=1.346 ms
16 bytes from fe80::200:e8ff:fe6c:557b, icmp_seq=7 hlim=64 time=1.354 ms
--- fe80::200:e8ff:fe6c:557b ping6 statistics ---
8 packets transmitted, 8 packets received, 0% packet loss
round-trip min/avg/max = 1.338/1.463/2.111 ms
Also that connection is running over my wireless, pretty fast I thought. :)