USB booting :: Can I save files?

I'm loading from an SD card using Qemu and a usb card reader. It's pretty slow, but I think it could be pretty cool for using at school and transfering files and apps. My question is though, how can I store files from DSL? As far as I know I can't save files onto my usb device from DSL in Qemu. Can I? I also will need to be able to store myDSL apps such as abiword.

Thanks,
-Peter

original here.