Laser control of the trapped ion electronic or hyperfine states provide precisely controlled quantum systems well isolated from environmental decoherence. Recent experiments have demonstrated small entangled ion systems with from two to eight ions. This talk will explore ion trap array designs that can entangle larger ion systems, possibly as large as 100 ions. These scalable ion trap arrays are fabricated using silicon VLSI techniques and will also accommodate integrated optics for precision laser control. Applications of these large entangled states to logical qubits, quantum simulation, quantum repeaters and cluster states will be discussed.