One step closer to the Heart of Gold

Via Crooked Timber, we find this: Quantum computer solves problem, without running:

'In a sense, it is the possibility that the algorithm could run which prevents the algorithm from running,' Kwiat said. 'That is at the heart of quantum interrogation schemes, and to my mind, quantum mechanics doesn't get any more mysterious than this.'

Oh, and the answer they found? I believe it was 42.