Hard drive install (upgrade) from USB drive?

[Wil Cooley]

On Wed, 06 Jun 2007 21:46:31 +0000, Wil Cooley wrote:

> According to the installation guide, I should be able to do a hard drive
> installation from sources on a USB drive:
> 
> (from
> http://docs.fedoraproject.org/install-guide/f7/en_US/sn-installing-from-
harddrive.html)
> 
> "Once you have booted your computer, you may use ISO image files of the
> Fedora discs to continue the installation process. The ISO files must be
> located on a hard drive that is either internal to the computer, or
> attached to the machine by USB."
> 
> My experience, however, is that it does not work; when I boot into the
> installer and am prompted for sources, my USB drive is not among the
> options presented as source partitions.

Let me broaden my question a bit: Has anyone actually installed or upgraded
from an ISO file residing on a filesystem on a USB mass storage device?  
(USB CD/DVD-ROM doesn't count.)  If so, how did you boot?

Wil