  We propose a new Monte Carlo scheme to study the late-time dynamics of a
2-dim hard sphere fluid, modeled by a tethered network of hard spheres.
Fluidity is simulated by breaking and reattaching the flexible tethers. We
study the diffusion of a tagged particle, and show that the velocity
autocorrelation function has a long-time $t^{-1}$ tail. We investigate the
dynamics of phase separation of a binary fluid at late times, and show that the
domain size $R(t)$ grows as $t^{1/2}$ for high viscosity fluids with a
crossover to $t^{2/3}$ for low viscosity fluids. Our scheme can accomodate
particles interacting with a pair potential $V(r)$,and modified to study
dynamics of fluids in three dimensions.
