ubuntu 10 has a usb key install that creates a .casper file that contains all your session and home data, it sits in the root of the key next to the the root filesystem, its like a live disk with a session file.
not all bios support usb startup though, and most locked down systems in business or education will have that bios option disabled to deter hacking from a key inside the network.
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Ours is the age that is proud of machines that think and suspicious of men who try to.
H.M. Jones
They say "Sing while you slave, but I just get bored" - B.Dylan