Nonlinear photonic crystals are materials in which the second order susceptibility is modulated, while the linear susceptibility remains constant. These structures are often used in nonlinear optics applications for compensating the phase mismatch between interacting waves. The progress in modulation techniques, mainly by electric field poling of ferroelectric crystals, enables to explore new applications, based on all-optical control of the phase, amplitude and polarization of the nonlinearly generated waves. This enables the realization of functional nonlinear optical devices, such as nonlinear lenses, switches, polarization rotators, deflectors and beam shapers. Here we will discuss in detail two applications - all optical polarization switching in a cascaded nonlinear photonic quasicrystal, and the generation and manipulation of accelerating Airy beams in two-dimensionally modulated crystals.