[Hampshire] Convert VMWare files into .ISO

I've been working on a highly customised configuration based on Ubuntu.
The eventual target is for it to be booted from a USB stick but all the
development has been done in a vmware image.

Has anyone any guidelines about how to take the data in the VMWare image
files and turn it into something that I can eventually burn into a
bootable USB.
What I'm working on is as follows:-
The configuration is aimed at a portable PORTAL gateway.
Portable == USB stick
PORTAL == runs Firefox in KIOSK mode with a homepage that points at a
customer portal.

There are customised boot screens and none of the normal Ubuntu splash
in Orange or progress bar.


Stephen D