Well I wouldn't want to even attempt to boot from a pen drive it would be way too slow compared to an HD, as for how it's done, don't ask me as I doubt it could be anyway... 
You can't even boot from USB on any of the iMacs I use it needs an external firewire drive to boot from another source, thing is why would you want to boot from a USB storage device in the first place, as I say It's way slower than an HD... :confused:
I'm running my A2000/060 and A3000/040 completely on USB sticks plugged into Deneb USB controllers. Works very nicely. I also, using the Icaros guide listed very early in this thread, have run and installed AROS from USB sticks. I have a Dell Mini 9 netbook with Mac OS X Snow Leopard running on its SSD and AROS running from a USB stick when I want to run that OS. It's a pretty speedy and responsive little system in either case.
Anyway, I stumbled a bit at first, as the thread starter has, trying to make it work. But following the guide to the letter will result in success.
