Phase-change chalcogenide alloys, such as Ge2Sb2Te5 (GST), have very different optical properties in their amorphous and crystalline phases. The fact that such alloys can be switched, optically or electrically, between such phases rapidly and repeatedly means that they have much potential for applications as tunable photonic devices. Here we incorporate chalcogenide phase-change films into a metal-dielectric-metal nanogratings and design perfect absorbers and beam steering devices for operation at technologically important near-infrared wavelengths, specifically 1550 nm. For perfect absorbers, we conduct an in-depth analysis of how design parameters of the structure influence the performance of the final devices. In particular, we show (both by modelling and through experiments) how one can achieve critically coupled absorbers and absorbers with desired quality factors. Then, we report on the design, fabrication, and characterization of innovative, non-volatile and reconfigurable beam steering nanogratings. Our devices reflect an incident optical beam in a mirror-like fashion when the phase-change layer is in the crystalline state, but reflect anomalously at pre-designed angles when the phase-change layer is switched into its amorphous state