livecd-iso-to-disk.sh is a Bash shell script from livecd-tools, http://git.fedorahosted.org/cgit/livecd/tree/tools/livecd-iso-to-disk.sh
In a LiveCD distribution, the script is usually available in the installation disc's filesystem at /LiveOS/livecd-iso-to-disk (alongside squashfs.img and osmin.img). From a booted LiveOS filesystem, the outer USB/SD/CD/DVD device filesystem is mounted on the /run/initramfs/live/ mount point (or at /mnt/live/ on Fedora 16 and earlier).
Usage is documented in the first 270 or so lines of the the script, and accessible with the livecd-iso-to-disk --help command. Documentation is also in livecd-iso-to-disk.pod, http://git.fedorahosted.org/cgit/livecd/plain/docs/livecd-iso-to-disk.pod , but the format may be less clear for reading.