Domain Wall Dominated Universes

We consider a cosmogony with a dark matter component consisting of a network of frustrated domain walls. Such a network provides a solid dark matter component with $p=-(2/3)\rho$ that remains unclustered on small scales and with $\Omega_{\rm dw}\approx 0.7$ can reconcile a spatially flat universe with the many observations indicating $\Omega_{\rm m}\approx 0.3.$ Because of its large negative pressure, this component can explain the recent observations indicating an accelerating universe without recourse to a non-vanishing cosmological constant. We explore the viability of this proposal and prospects for distinguishing it from other kinds of proposed dark matter with significant negative pressure.