Most existing models of portable computing require users to carry their computing environments together with their computing hardware. This paper proposes a paradigm for portability that separates the computing engine from the user’s state. The idea is to capture the user’s working set and recent updates on a highly-portable flash memory device. We imagine that homes, offices, meeting rooms, and public places have or will have sufficient hardware to efficiently instantiate user desktops in the presence of such flash devices. The cost and convenience of flash memory makes carrying a cache or a partial replica of your computing environment a plausible alternative.