Quantum-mechanical interference between indistinguishable quantum particles profoundly affects their arrival time and counting statistics. Photons from a thermal source tend to arrive together (bunching) and their counting distribution is broader than the classical Poisson limit. Electrons from a thermal source, on the other hand, tend to arrive separately (anti- bunching) and their counting distribution is narrower than the classical Poisson limit. Manipulation of quantum-statistical properties of photons with various non-classical sources is at the heart of quantum optics: features normally characteristic of fermions - such as anti-bunching, sub-poissonian and squeezing (sub-shot-noise) behaviours - have now been demonstrated. A single-photon turnstile device was proposed to realize an effect similar to conductance quantization. Only one electron can occupy a single state owing to the Pauli exclusion principle and, for an electron waveguide that supports only one propagating transverse mode, this leads to the quantization of electrical conductance the conductance of each propagating mode is then given by G(Q) = e2/h (where e is the charge of the electron and h is Planck's constant; ref. 9). Here we report experimental progress towards generation of a similar flow of single photons with a well regulated time interval.