If your notebook support USB, it should boot from USB drive. Look at this article: http://www.gentoo.org/doc/en/liveusb.xml
Topics (messages 405 throught 405):
[gentoo-laptop] usb boot
405 - Gavin Seddon <gavin.m.seddon@manchester.ac.uk>
I have found info on the web about booting onto a flash. However, all
appears spurious at best. I want to put gentoo and ubuntu on a flash
(not at same time). Will my t42 boot off usb? If so can anyone
outline howto?
Thanks.