Sorry no save feature on the iPhone... I know, I know, lets hope they update that. I was talking to a guy that works for Apple and I asked about this. He said he only sees it happening if they can section it off from the OSX section so people can't tinker around with OSX.
My thought is wouldn't this be easy to do?
Can't they just create a image that mounts that can increase and decrease in size, kind of like how Virtual Machine disks do?