standard recipe for creating a multiboot SD card?

is there a recipe online somewhere for creating a multiboot SD card,
so i can fill it full of various bootable images and not have to keep
swapping SD cards on my xM?

  i know innovative computing has such an image -- the "super-jumbo"
image documented here:

i can just use that as the basis if people agree it's a reasonable

  i know i can use the "User" button to switch between *two*
possibilities, but i want to load as many bootable possibilities as i
can, perhaps even adding panda images if there's room.

  right now, canada computers down the street has a class 10, 32G
micro SD card for $54, and that's probably big enough for everything i

  so ... pointers? thanks.