Sorry my friend, I really cannot see where this is going.

Why the hell would I want to run Maemo on my 22" monitor instead of Windows or Linux or OSX? Also, where is this "data" stored. When you plug it into the computer, just the memory cards get mounted. Apps don't write data like settings to memory cards.

What you are referring to is probably some complicated chroot setup, in which a stripped down Linux system is monitoring if it is plugged in or not, and if it is not, it runs the ARM version, and if it is , it runs the x86 version. For this you would need a 1:1 compatible ARM vs x86 maemo, because they would be sharing everything except binaries.

c o m p l i c a t e d.

The million dollar question is, what are you trying to accomplish? Most public terminals DO NOT allow booting from USB, for obvious reasons. In fact, most libraries and stuff usually run a server farm in the basement, and all the PC's are simply running remote desktop into the servers. This gives them very easy maintainability.