There is a 6.0 GB USB pendrive image .. and a 4.8 GB boot.iso for network installs here:
http://mirror.centos.org/centos/4/os/i386/images/
(substitute your arch for i386 if different)
I'm assuming you mean 6 MB and 4.8 MB of course :) 6 GB would fit i386+x86_64 bin install with updates :)
nb. No comments on my jigdo thread post?
Cheers, MaZe.