Step one: Get the file
C:\ubuntu\disks\ to a Ubuntu machine. I (now quad) dual boot Ubuntu and Windows, so I just mounted my Windows partition in Ubuntu.
sudo apt-get install ecryptfs-utils
sudo mkdir /vdisk
sudo mount -o loop $PATH-to-root.disk /vdisk
To make sure you're in the right spot, run
ls /vdisk/home - if it says something like
jrg (or whatever your username is), then you're in the right place.
sudo ecryptfs-recover-private and follow the prompts.
Your home directory will be mounted (read-only and decrypted) in
Then, to view your data, you need to run
gksu nautilus /tmp in a terminal, then select the ecryptfs.whatever dir - all your data will be in there.
Enjoy your recovered data!