The bigger problem is stress. Nomadic work means more autonomy, but “anybody who works for himself has a tyrant as a boss,” says Paul Saffo, the Silicon Valley trend-watcher. “The danger is that the anytime, anyplace office will lure us into the tiger cage that is the everytime, everyplace office.” BlackBerries and their kin have already caused marital problems for many couples, who must negotiate whether the gadget is allowed, say, in the bedroom or on the beach while on holiday. Severe addicts pretend to go to the lavatory at home just to check their e-mail. An office worker's day used to stop when he left the office. When does a nomad's working day stop?