Wearable storage
The Soulpad is IBM's idea of wearable storage. But the idea is a bit more: independed computing. Usually wearable computing is about an own application with it's own computing system, storage, network and processes. But usually you already use a computer, applications etc. This way when a computer can be hardware or software this is the software version of a wearable computer.
SoulPad is a portable storage device containing the software stack shown below. The three-layer SoulPad software stack enables a paradigm of mobile computing where a user can suspend his computing environment on one PC and resume it on another PC that he may have never seen before.
Your whole PC in a tiny box. The extern devices are "borrowed". After I've seen a high-power notebook build into a belt I think that vision makes sense.
Video here (14MB) and here (91MB)
USB 2.0 is fast enough that the performance bottleneck is not the communication link between the SoulPad and the PC. Further, many PC BIOSes support the ability to boot directly from USB disks simplifying the resume operation to one of connecting the SoulPad over USB 2.0 and instructing the PC BIOS to boot from USB. Since the SoulPad device carries the entire personal computing state of a user, it is important that the storage capacity of the device be large enough to hold all of the content that the user needs.