Do you often use someone else's PC, and need to access your own apps? There's a whole culture out there around apps that will run off a USB key (portable Firefox for example.) Steve Makofsky of The Furrygoat Experience has taken it a step further and developed a launch script for the Pocket PC emulator that will run from a USB key. You can even install Pocket PC apps to the key. I don't have a use for this, since I carry a Pocket PC, but its cool anyway.