The controlled creation of entanglement is one of the most challenging goals of modern quantum physics. Here we show how spin dependent optical lattice potentials together with controlled collisions between atoms in an optical lattice potential can be used to realize massively parallel operating quantum gates. In a second experiment, the generation of Bell states of atom pairs on single lattice sites is demonstrated by employing a newly found interstate Feshbach resonance in 87Rb. This Feshbach resonance has allowed us to efficiently modify the scattering length between two atoms in different spin states and is used to induce an entanglement dynamics in the system.