A common topic on Slashdot is the fact that many Linux distributions create Live CDs that can boot Linux and yields a desktop anywhere. The first time I ever saw this was when a friend of mine was playing around with Slackware Linux...back in 1994, I think.
Some people use this in combination with portable media like a USB Zip drive or a USB thumb drive to keep settings and other stuff.
Is this something Microsoft could do with Windows? It'd be great to just sit down and boot into Windows XP wherever I want.