  It has been conjectured that four-dimensional N=8 supergravity may provide a
suitable framework for a `Theory of Everything', if its composite SU(8) gauge
fields become dynamical. We point out that supersymmetric three-dimensional
coset field theories motivated by lattice models provide toy laboratories for
aspects of this conjecture. They feature dynamical composite supermultiplets
made of constituent holons and spinons. We show how these models may be
extended to include N=1 and N=2 supersymmetry, enabling dynamical conjectures
to be verified more rigorously. We point out some special features of these
three-dimensional models, and mention open questions about their relevance to
the dynamics of N=8 supergravity.
