Hello everyone!

I was wondering if it was possible to boot an OS off a pen drive ,just like how we use mmc to run other OSes.
I live in India,and class 6 and higher memory cards are very tough to come by.
i mean extracting the file-system to the pen drive and booting off it(connecting it to your N900 just as you connect it when using h-e-n, through a female-female USB converter).
Is it possible?

p.s--feel free to correct me if you think i am wrong or don't know what I'm talking about!