Doing one thing at a time seems to be a vanishing art, and in fact many of the situations people put themselves in do not even allow for such a unified state of mind. The busyness and confusion that so often accompanies multi-tasking takes a toll, however, and it not usually a rewarding, or even healthy, way to use the mind. Consciousness is a precious resource, and if it is spread too thinly by trying to manage multiple factors at once, its coherence diminishes.
Andy Olendzki
online sutta study
You can participate in this work with Andy by visiting the website of the Barre Center for Buddhist Studies or join me as I work with his study on the Practice Board http://citta101.com/practice/.