LinuxBSDos.com posted a tutorial about installing edora 15 on an encrypted btrfs file system

Fedora 15, the latest stable release of the Red Hat-sponsored Linux distribution, is the first Fedora release to have btrfs, the B-tree File System (also called Butter F S), as a file system option during the installation process. On earlier versions, you would have had to pass the btrfs option to Anaconda at boot time to install Fedora on a btrfs file system.

In Fedora 15, the btrfs option is available only on a DVD and bfo ISO installation image. A Fedora 15 DVD image weighs in at 3.4 GB, while a bfo image is just 670 KB. Using a bfo image allows you to perform a network installation

  How to install Fedora 15 on an encrypted btrfs file system