  We study the velocity autocorrelation function (VACF) of a driven granular
fluid in the stationary state in 3 dimensions. As the critical volume fraction
of the glass transition in the corresponding elastic system is approached, we
observe pronounced cage effects in the VACF as well as a strong decrease of the
diffusion constant. At moderate densities the VACF is shown to decay
algebraically in time (t^{-3/2}) like in a molecular fluid, as long as the
driving conserves momentum locally.
