Alright, there is a way to do what you want to do.
You'll need to have either a large usb-harddrive or a large usb-flash drive (an 8GB flash drive will do fine.) You must also be connected to the Internet for when the installer refreshes the repositories.
First you must install yast2-live-installer.
Then plug in your usb device and run the live-installer.
Agree to the license terms and click next.
Choose your time zone then click next.
Click Create Partition Setup.
Choose your usb device (it will be the /dev/sdb) then click next.
Tell the installer you want to Use entire hard disk then click next.
Click Edit Partition Setup. Choose Hard Drive and then choose /dev/sdb. Delete the partitions it has set up. Click Add. Choose Primary Partition and click next. Choose Use Maximum Size then click next. Make sure it's set up like this screen.
Then click finish.
Click accept and then click next.
For the username and password setup this is just a live-usb so it doesn't have to be high end security. It could be something as simple as
username:linux
password:livecd
After you've chosen these click next and if it says something about a weak password just click yes twice.
This will bring up the installation summary page. Click on the category Booting. Down on the bottom right click on Other then choose Propose New Configuration.
Then click on the Boat Loader Installation tab. Only place a check next to boot from root partition.
Click Ok.
Last, choose install and wait for your live-usb to be made! Once it's done restart your computer and tell it to boot from usb to make sure it works.
Hope this helps!
Ian