Originally Posted by zeus_zf
I hope this makes sense. In other words, I have my bt3 running from a ISO, and a thumbdrive filled with files.

I guess the question is, is it possible to read and write to the usb, without having to install bt3 itself, if so, what would be the appropriate steps to this answer?
Yes it is possible, only thing needed is to insert the USB stick once booted into BT3 and it should automatically map the drive for you. At this point you will be able to access the USB stick and both read and write to it. If you are having problems with this it might be that you have to manually map the drive, and the steps for this can easily be found through google or posted on this forum.