"Mk-boot-usb is a perl script to create multiple-bootable USB
sticks (USB keys/USB flash drives). It wipes out an entire USB
stick, partitions it, creates file systems on it, installs grub,
and installs a minimal Linux on it. Mk-boot-usb is meant to speed
up and lower the barrier of entry for creating bootable USB sticks.
The USB stick will immediately become bootable (using the minimal
Linux), and more useful distributions can then be installed into
other partitions manually simply by (1) copying any Live CD into
each partition (2) modifying grub's configuration file.
"This program will destroy all of your data in the USB stick. It
may even destroy all of your data in the harddisk and/or those on
any storage device attached to it if you are not careful..."