Title: Quantum Diffusion and Delocalization for Band Matrices with General Distribution Abstract: An introduction to "Quantum Diffusion and Delocalization for Band Matrices with General Distribution" by Laszlo Erd?s and Antti Knowles, Ann. Henri Poincare (2011, online), http://dx.doi.org/10.1007/s00023-011-0104-5 and http://arxiv.org/abs/1005.1838/