Multi Boot With Grub 2#

Just some notes. You will get this, if this is for you:

fdisk /dev/sdb
# WARNING pull stick, reattach (else grub-install could have problems probing the device)
mount /dev/sdb1 /mnt
grub-install --no-floppy --recheck --root-directory=/mnt /dev/sdb
mkdir /mnt/iso

# tmpdir to mount images
mkdir -p /tmp/img

For each iso:

# copy image to /mnt/iso
mount -o loop /mnt/iso/IMAGE_NAME /tmp/img
# inspect syslinux loader for kernel args
umount /tmp/img

Ubuntu server 12.04 x64:

cat <<'EOF' >> /mnt/boot/grub/grub.cfg
menuentry "ubuntu-12.04-server-amd64" {
  set isofile="/iso/ubuntu-12.04-server-amd64.iso"
  set kernel=/install/vmlinuz
  set ramdisk=/install/initrd.gz
  loopback iso (hd0,1)${isofile}
  linux (iso)${kernel} boot=install iso-scan/filename=${isofile}
  initrd (iso)${ramdisk}
}

EOF

Backtrack 5 R3 KDE x64: http://www.backtrack-linux.org/forums/showthread.php?t=42735

Postprocessing:

sync
umount /mnt
# pull stick, attach to target, enjoy

Sources: