I don't know about SuSE, but Damn Small Linux and PuppyLinux both boot well from USB/mini CD. DSL even has the option of installing as a complete Debian on your USB device.
Ofcourse if you absolutely must have SuSE, that's probably not going to do you any good at all.
Ofcourse if you absolutely must have SuSE, that's probably not going to do you any good at all.