Hi,
I downloaded the openSUSE 11.1 liveCD(GNOME version) iso & extracted its content to /openSUSE folder in my ext3 drive then added following lines to my GRUB bootloader.
title openSUSE-11.1
kernel /openSUSE/boot/x86_64/linux
initrd /openSUSE/boot/x86_64/initrd

booting occurs but stops with message
'couldn't find live image configuration file.'
the idea about installing from iso without wasting CD or DVD came from Stop Wasting CDs; Install Linux Straight from an ISO – LINUX For You Magazine
My specifications are.
core2Duo 3GHz processor,2GB RAM & 40GB ext3 partition .