  We propose protocols for the creation of useful entangled states in a system
of spins collectively coupled to a bosonic mode, directly applicable to
trapped-ion and cavity QED setups. The protocols use coherent manipulations of
the spin-boson interactions naturally arising in these systems to prepare spin
squeezed states exponentially fast in time. We demonstrate the robustness of
the protocols by analyzing the effects of natural sources of decoherence in
these systems and show their advantage compared to more standard slower
approaches where entanglement is generated algebraically with time.
