Here's how I've set it up on my home Debian server so that it will provide IPv6 addresses to my home network:

1. Add +ipv6 to /etc/ppp/peers/dsl-provider
2. I had to change the username in dsl-provider and in /etc/ppp/chap-secrets to use a different hostname, as this is how Internode knows you want to connect to the IPv6 trial server.
3. Start the DSL connection with "pon dsl-provider", resulting in a connection ppp0 which has both an IPv4 internet address, and a local fe80:: IPv6 address
4. Ensure eth0 has a local IPv6 address too, using ifconfig. I was messing about and lost it, and got it back by resetting with ifdown eth0; ifup eth0
5. Now to get a real IPv6 prefix you need an IPv6 DHCP client. At Internode's suggestion I installed the WIDE client (package wide-dhcpv6-client in Debian). The given working configuration for a PPP connection ppp0 and local ethernet connection eth0 is placed in /etc/wide-dhcpv6/dhcp6c.conf as follows:
   interface ppp0 {
send ia-pd 0;
script "/etc/wide-dhcpv6/dhcp6c-script";
};
id-assoc pd {
prefix-interface eth0 {
sla-id 0;
sla-len 4;
};
};
6. When you install the WIDE DHCPv6 client it starts automatically, with an non-useful config. Restart it with invoke-rc.d wide-dhcpv6-client restart. Hopefully now an "ifconfig" will show that you have successfully attached a 2001:: prefix address to your eth0 interface.
7. Add a default route -- this doesn't happen automatically. Run the command:
   route --inet6 add default dev ppp0
   This will add a default route through the gateway on your PPP connection.
8. At this point there is working IPv6 connectivity on the local machine. It can be tested with "ping6 ipv6.google.com":
   # ping6 ipv6.google.com
PING ipv6.google.com(tx-in-x68.1e100.net) 56 data bytes
64 bytes from tx-in-x68.1e100.net: icmp_seq=1 ttl=56 time=171 ms
64 bytes from tx-in-x68.1e100.net: icmp_seq=2 ttl=56 time=172 ms
9. To set up advertising of addresses and routing I referred to Martin Krafft's excellent IPv6 with Debian documentation. In summary, the configuration I had to do was to set /proc/sys/net/ipv6/conf/all/forwarding to 1, which can be made permanent by setting it in /etc/sysctl.conf, and to set up radvd.
10. radvd (which is also the name of the package) will provide IPv6 addresses from the allocated /64 prefix to hosts on the local network. Install the package. I set my /etc/radvd.conf to the following, which uses the prefix I was allocated, as found from ifconfig:
    interface eth0
{
AdvSendAdvert on;
AdvLinkMTU 1280;
prefix 2001:44b8:7c90:be0::/64
{
AdvOnLink on;
AdvAutonomous on;
};
};
11. Now other machines with IPv6 support which are connected via the eth0 interface should be allocated an address and will be able to access the IPv6 Internet too.

I have a fun ISP who gives me toys to play with. :)

Today I'm going to present a possible solution to the first complaint: poor file format support. The accepted way to extend your OS X machine to play (oddball?) formats like FLAC seems to be to install the Xiph components for Quicktime. In my experience, this will usually convince Quicktime to play most things. Getting iTunes to look at the songs and store them in your library is another matter entirely. The best success I ever had with this method was getting about 1/3 of my considerable collection of FLACs to import.

Let's fix things up with a little bit of Firefly. No, not the unbelievably awesome Joss Whedon show (blast you, Fox!) but the also rather awesome Firefly Media Server, formerly known as mt-daapd. I last played with this project a couple of years ago and it took some tinkering to make it work. There's been a bit of work done since then and now the latest build is in the Debian stable repository, so it's dead simple to set this up now.

"Debian? Isn't this a problem with iTunes on OS X?" you might be wondering to yourself now. Yes. You're right. Allow me to present the recipe for this particular solution:

iTunes Make Support Go-Go

Ingredients

• One computer running Mac OS X with iTunes
• One computer running Debian Linux
• Your music in any of normal formats: MP3, OGG, FLAC, WMA, etc. stored on the Linux computer
• Firefly Media Server
• A LAN connecting to the two computers

1. Install the package with aptitude install mt-daapd
2. Edit /etc/mt-daapd.conf and set admin_pw to an admin password, mp3_dir to where your music is (with a trailing slash) and add any file extensions to the list of those it will serve. In my case, I had to add wma. You can also change the name of your server if you like.
3. /etc/init.d/mt-daapd start
4. Head to iTunes on the mac and notice either the name you set or "Firefly ..." appears in the shared libraries list.
5. Play your music. Observe how you can play songs in all formats regardless of whether iTunes supports them directly.

The magic at work here is that Firefly will use ffmpeg to transcode any songs not natively supported by iTunes on the fly to uncompressed wave format.

One extra advantage is that you no longer need to use all the hard drive space on your mac, which can be handy if it's a laptop. One disadvantage is that you can only listen to your music when you're on the same LAN as the Linux box. Perhaps you should have thought about that before you paid the Mac tax and expected them to support your open formats properly. *sigh*

(serves as many as your Firefly server has the bandwidth to serve)