http://www.theregister.co.uk/2008/05/12/fedora_9/.
Perhaps the most interesting news in Fedora 9 is the release of what amounts to a complete live, carry-anywhere USB solution. The ability to create a Live USB stick from the LiveCD media was part of earlier Fedora releases, but the ability to have persistent data and to do a non-destructive install are both new. Headed to a friend's house and don't want to use Vista? [Has it come to that - Ed?] Just bring along your LiveUSB and boot up. Any changes you make, documents you create or software you install will all be saved to your USB drive and available the next time you plug it in. And that applies not just to user installed files and apps, but the system as well, which means any system update you find will be part of your Live USB partition. And if your friend wants a copy of Fedora, no problem. Just install Fedora on a USB stick with sufficient space and any existing files on the disk will be left intact.
Wow!