The Holographic Principle, although its best-studied realisation arguably lies within the AdS/CFT correspondence, is believed to hold in rather general circumstances. In this talk, I will motivate the search for holographic dualities involving (asymptotically) flat spacetimes and discuss some of the peculiarities that arise in Flat-Space Holography. In the particular case of (2+1)-dimensional bulk spacetime, I will emphasise the role played by massive fields and particles as holographic probes and present an algebraic approach to the coupling of massive fields that utilises techniques of higher-spin theory.
