After an introduction into the subject we show how one constructs a canonical
formalism in space-time noncommutative theories which allows to define the
notion of first-class constraints and to analyse gauge symmetries. We use this
formalism to perform a noncommutative deformation of two-dimensional string
gravity (also known as Witten black hole).Comment: Based on lectures given at IFSAP-2004 (St.Petersburg), to be
submitted to Theor. Math. Phys., dedicated to Yu.V.Novozhilov on the occasion
of his 80th birthda