How To Upgrade Ubuntu 9.04 to 9.10 Using An Alternate CD

http://www.ubuntulinux.org/getubuntu/upgrading#Upgrading%20Using%20the%20Alternate%20CD/DVD

http://mirror.anl.gov/pub/ubuntu-iso/CDs/karmic/

Only one caveat: I never tried using this procedure, I always do network upgrades using the Update Manager because it's much simpler.