multiboot flashdrive suggestions

[Trio3b]

Pretty much settled on three distros to create a single bootable flashdrive so I can run either Live versions or straight installs on a variety of somewhat older hdwr. PCLOS, Mageia, and LinuxMint (including 3-4 variations of each distro), so there would be maybe 10-12 isos being used to create the drive. I have created bootable flashdrives of each of these distro pretty easily. Here's the problem. Unless I am mistaken, each distro uses a different method to install on the drive, so I have a dozen or so flashdrives and SD cards laying around.

PCLOS USB Creator requires ext 2 or 3 and uses its own script and is not usable with other distro's .isos. The script does allow for several isos on the same drive.
Magiea is a hybrid kernel and if I remember, I just dd 'd the iso onto the drive (ext 4 partition I think)
With LM I used unetbootin and I think it wanted a FAT32 partition.

So any suggestions about how to partition the drive, use grub and then install about a dozen distros on ONE 16 gb flashdrive?
Better options?

Thanks

[filip]

You can take a look at this tip about RMPrepUSB. I tried it successfully.