liveusb-creator

"The liveusb-creator is a cross-platform tool for easily installing live operating systems on to USB flash drives.

Features

* Supports downloading various Fedora releases, including Fedora 9!
* Persistent overlay creation (only works with Fedora 9 right now). This lets you to allocate extra space on your USB stick, allowing you to save files and make modifications to your live operating system that will persist after you reboot. This essentially lets you carry your own personalized Fedora with you at all times
* SHA1 checksum verification of known releases, to ensure that you've downloaded the correct bits"

https://fedorahosted.org/liveusb-creator