Desktop edition, 32-bit:
http://releases.ubuntu.com//intrepid/ubuntu-8.10-desktop-i386.iso

Desktop edition, 64-bit:
http://releases.ubuntu.com//intrepid/ubuntu-8.10-desktop-amd64.iso

Server edition, 32-bit:
http://releases.ubuntu.com/intrepid/ubuntu-8.10-server-i386.iso

Server edition, 64-bit:
http://releases.ubuntu.com/intrepid/ubuntu-8.10-server-amd64.iso