Peapod nanocomposites can be readily fabricated by the in situ growth of gold within scrolled nanosheets or partially filled Fe3O4 hexaniobate nanopeapods. In their Communication on page 4614 ff., J. B. Wiley et al. report the synthesis and characterization of both gold and gold–Fe3O4 hexaniobate nanopeapods. The composites show variation in optical and magnetic properties as a function of composition.