What about portable-qemu?
It's not vbox or vmware, but it is portable, plays multiple systems on windows or linux
from iso, virtualharddrive, etc
plays on any type partition, on usb, off cd, etc
portable-qemu(mine) has kvm for linux and is 3mb before making a vhd.
also, only thing needed to play portable-qemu is SDL.tce library, no need to install qemu to tinycore.
you can access your real hd/usb/cddrive and it all runs just like a real system.
just a thought