We have just added a paper to the growing collection of experimental implementations of quantum walks. Quantum walks are the quantum analogue of random walks in the classical world. The theory of quantum walks has long been established, but only last year saw a number of decent experimental realizations, with neutral atoms, ions (here and here) and, of course, photons.
What makes our quantum walk special is that we can control the amount of decoherence in the walk. Decoherence, i.e. loss of coherence in the quantum system by interaction with the environment, is at the heart of many of the quantum protocols and biological processes that have partly spurred this renewed interest in quantum walks. We expect to use our new toy for a number of experiments on these phenomena in the near future.
EDIT: The paper has now been published in PRL.