large usb2 hard disk drive booting diff computers?

[Heitzso]

Quick question ...

I have an app for a client in which I need to have Linux
booting and running from a 300G USB2 drive when attached
to a computer, and 4 or 5 different computers involved,
i.e. the one USB2 drive must be able to clean boot on
several different computers.

There are a number of mini-distros w/ instructions for
loading and booting from a USB thumb drive where
everything is compressed and boot process makes NO
assumption about what computer it is attached to.
I don't want/need the compression, but I do need that
"I don't know what computer I'm attached to now"
mentality when booting.

If I do a straight Ubuntu install to a USB drive then
take that USB drive to another computer and plug it
in will I be able to do a reasonable boot on that new
box?  (assuming set BIOS to boot off USB or boot from
side CD/floppy to force boot of USB drive)

Gotchas?

THANKS

p.s.

The app is to use a third party computer in another city
to grab 60 hours of victim's rights interviews over firewire
(miniDV original format) at the production house responsible
for the miniDV recordings, then take transcripts in MS .doc
format (already prepared by the production house)
with embedded timecodes and munge the transcripts
over to PHP files with the timecodes turned into A HREF
html tags to go to a PHP script that lets the user select
segments of an interview to watch and/or burn to CD/DVD
in DVD quality MPEG 2 file format.  Hence almost 300 G
worth of MPEG 2 files.  Target site is a standalone
computer at a University's library.  nanoweb is webserver.
dvgrab/ffmpeg/etc. tools to grab/compress/manipulate video.