Okay, here's a boot-from-flashdrive solution:
http://en.kioskea.net/forum/affich-9...-t-boot-up#258
[EDIT]
Grah! A 'success' comment there had me thinking that someone had managed to install from the flash drive, but he had a USB DVD drive hooked up so that he could use the installation disc. *dang*
[FURTHER EDIT]
Here, have a look at this, Xabba.
http://en.kioskea.net/faq/3065-insta...from-a-usb-key
Is that close to what you are looking for?