When a photon beam from a light source is split in two, with one part transmitted and the other reflected at a half-silvered mirror, it is found that the intensities of these beams are correlated: the photons exhibit "bunching," that is, they tend to come in clusters of identical particles occupying the same state. In contrast, electrons are expected to exhibit "antibunching" and therefore a negative intensity correlation. Büttiker (page 275) discusses two successful measurements of such antibunching of fermions in mesoscopic conductors (Henny et al., page 296, and Oliver et al., page 299) and explains why their approach is important for investigating a range of subjects from superconductivity to noise suppression in quantum computing.