  We construct relativistic equilibrium models of differentially rotating
neutron stars and show that they can support significantly more mass than their
nonrotating or uniformly rotating counterparts. We dynamically evolve such
``hypermassive'' models in full general relativity and show that there do exist
configurations which are dynamically stable against radial collapse and bar
formation. Our results suggest that the remnant of binary neutron star
coalescence may be temporarily stabilized by differential rotation, leading to
delayed collapse and a delayed gravitational wave burst.
