superposition of disbelief? Good, because the latest news published in Nature is that diamonds are a quantum computer's best friend -- particularly if they're flawed. An international team of scientists sought out sub-atomic impurities in a 1mm-thick fragment of over-priced carbon and used these as qubits to perform successful calculations. A "rogue" nitrogen nucleus provided one qubit, while a free electron became a second. Unlike previous attempts at solid-state quantum computing, this new effort used an extra technique to protect the system from decoherence errors: microwave pulses were fired at the electron qubit to "time-reverse" inconsistencies in its spinning motion. Don't fully get it? Us neither. In any case, it probably won't stop jewellers tut-tutting to themselves.