Boot USB (or any device) through CD drive?

I know that it is possible to boot any device desired by using tools like Super Grub Disk, so what I'm wondering is how difficult (or easy) would it be to create a CD that when you boot it, it immediately just boots the USB drive?

Now, there are a few ways one could go about this I imagine:

1. you could boot the BIOS's list of hard drives in reverse order (we are assuming that the boot order is Floppy, CD, HD, and that HD is broken down into internal drive, then all "addons")
2. or possibly detect what is USB and boot the first thing found
3. or just show the user a list of devices and let them pick - (imagine GRUB, but give a list of devices instead of configured partitions)

My preference is not necessarilly in this order.

How hard might it be to create any one of those? Or do tools already exist to do this? (I need using it to be fast and easy like the examples above - possibly being even completely automatic, like #1 and #2)

I'm not sure if Smart Boot Manager will fill your needs but I'll throw it out there.

SourceForge.net: Smart BootManager

I have used it on Limited Bioses.

Yet Another Technology Site: installation

I noticed it had PCMCIA and USB boot Options in the menu. Never tried USB boot option though. You can make a CD instead of a floppy like I did.

I'll see if that can do the trick!