For the first three days of last week, I was holed up in a meeting room in Spain with a BlackBerry that stuttered into life only intermittently, feeling like a rat in the famous 1970s stress experiment.

These rodents were subjected to a series of electric shocks; some were given advance warning, while the rest were shocked out of the blue. The first group bore up rather well while the second suffered horribly, all coming down with stomach ulcers.

The BlackBerry outages left me feeling like the second set of rats. Over and over again I checked my little machine for signs of life. Nothing. Then, without warning, the red light would flash and a dribble of email would come through. But instead of feeling better I felt even more anxious. Was this all? When would more come?