NOTE: this will delete everything on the USB stick. 

Plug in USB (make sure it's unmounted), then:

wget http://giannaros.org/suse/kde-four-live-usb/KDE-Four-Live.i686-0.1 http://giannaros.org/suse/kde-four-live-usb/initrd-usbboot-suse-10.3.i686-2.1.1.gz
kiwi --bootstick initrd-usbboot-suse-10.3.i686-2.1.1.gz --bootstick-system KDE-Four-Live.i686-0.1