This volume contains papers presented at the NATO Advanced Study Institute (ASI) Photonic Crystals and Light Localization held at the Creta Maris Hotel in Limin Hersonissou, Crete, June 18-30, 2000. Photonic crystals offer unique ways to tailor light and the propagation of electromagnetic waves (EM). In analogy to electrons in a crystal, EM waves propagating in a structure with a periodically modulated dielectric constant are organized into photonic bands, separated by gaps where propagating states are forbidden. There have been proposals for novel applications ofthese photonic band gap (PBG) crystals, with operating frequencies ranging from microwave to the optical regime, that include zero­ threshold lasers, low-loss resonators and cavities, and efficient microwave antennas. Spontaneous emission, suppressed for photons in the photonic band gap, offers novel approaches to manipulate the EM field and create high-efficiency light-emitting structures. Innovative ways to manipulate light can have a profound iofluence on science and technology.