I've got a copy of Spotmau's Bootsuite 2012, which is an utterly fantastic tool. It has completely replaced Bart PE for me, and I relied on BPE for YEARS.

Anyway, the issue I'm having is that the Bootsuite installer utility will only create bootable USB flash drives, or bootable CDs. The USB hard drive is detected as a hard drive instead of as a USB device, and as such I cannot use the included app to install to the USB HDD.

Is there a way of either copying the files from a bootable flash drive to a USB HDD and making that work, or of taking an .ISO of the bootable CD and using that to make the portable HD bootable?

The flash drives I've made of it are great as I can always have it with me [have 16GB dangling from my keychain. :) ], but my USB hard drive is FAR faster than any flash drive I have, so I'd like to be able to use that when I'm working out of my office or happen to have it with me.