Install to USB without rebooting?

[Cybe R. Wizard]

I'd like to install a live Intrepid beta to a 4 gig USB stick but don't
want to reboot to do so.  Is there a way?
Everything I've googled is either about installing /from/ the USB stick
or involves some rebooting and access to the CDs installer after the
reboot. Can't it be done through a terminal (or GUI) without the
rebooting?

Cybe R. Wizard
-- 
Nice computers don't go down.
	Larry Niven, Steven Barnes
		"The Barsoom Project"