"What's more, when people do finally start working again, they
don't reach their earlier level of concentration for 10 additional minutes.
Total time that can be lost answering just one e-mail: a half hour, and that's
the best case scenario. "Every e-mail interruption is like a hand grenade being
thrown in the middle of your brain," says Dr. Hallowell."
This is an interesting article on too many distractions.