[CentOS] Install (not boot) from USB drive?

Is it possible to install directly from a DVD iso image downloaded to a 
USB external drive as a file on a FAT filesystem?  That is, if I burn 
the boot.iso on a CD and boot it, is there any way to mount the USB 
drive and install from the DVD image file there (some target machines 
don't have a DVD drive).

-- 
   Les Mikesell
    lesmikesell at gmail.com