Quantum entangled states are useful for fundamental checks of quantum mechanics and various protocols in quantum information. Polarization entangled states of photons are very popular due to their high entanglement quality and simple generation and manipulation. In the last 10 years, the state of two entangled photons (an EPR pair) has been studied extensively. When the entanglement involves more particles, new options are opened. Some examples are more robust quantum cryptography protocols and interferometric measurements that are more accurate than the Heisenberg limit. Another use of such states is the violation of large-spin Bell's inequalities. As these states are getting larger, the cross-over between the quantum micro world and the classical macro world can be probed.
     I will describe a few options for such states of large number of polarization entangled photons. Recent results that show the generation of entangled states that contain up to 100 photons will be presented.