http://www.youtube.com/watch?feature=player_embedded&v=XIZVcRccCx0 This primarily appears in horror and thriller films, and it's the most infuriatingly lazy way for a screenwriter to throw an obstacle in the way of the hapless characters trying to survive. So, the nubile young teens will rock up to whatever cabin/house party/orgy they're going to this week, and suddenly they will lose mobile phone reception (especially if it's in the middle of nowhere) or their battery will run out (more commonly in urban areas). It's literally the first thing writers can think of to stop the protagonists summoning help, and something that becomes more problematic for them the more prolific that smartphones and other devices become in real life. Though it's been overused for at least a decade, it just feels blatantly unrealistic now; in an age where most people treat their mobile phone as a life-line, it's not particularly plausible that most people wouldn't have a phone fully charged before leaving for a lengthy trip. I'm instantly turned off a film when I hear this, because it's usually indicative of a script that has zero imagination.