MacWorld reports that iPod zombies are scaring motorists and causing accidents in Great Britain. iPod zombies are bicyclists who pedal down the road with their iPod headphones plugged in. Yes, this means they can't hear road traffic, and worse, are probably mentally wrapped up in listening to the music instead of being aware of the traffic around them. How big a problem is it? The English Department for Transportation reports a 19% rise in serious injuries or death to bike riders this year compared to last year.