If the two flash drives are the same size you can use the dd command to make an exact sector by sector copy of the one flash drive on the other:
# dd if=/dev/sd* of=/dev/sd#
You must be root to run dd. The * should correspond to the device file for your initial flash drive, typically /dev/sda, and # should correspond to the device file of your second flash drive that you want to copy to, typically /dev/sdb. The numbering/lettering on your flash drives' device files will depend on the order in which you put them in the usb ports on most distros. Also, if you have any sata drives, they take up sdx numbering, i.e. the first sata drive is /dev/sda, so that will shift the first flash drive to /dev/sdb.
CAUTION: It is imperative that you get the device files right for your flash drives when using the above command. If your not sure how to do this, post back before trying to run the command.
At any rate, the dd command will work and the second flash drive will be bootable, just like the first.
Last edited by kilgoretrout; 01-18-2006 at 12:11 PM.