Here's an interesting subject for a PhD: the influence of the cell phone on society and culture.
I imagine the first significant cultural appearance of the cell phone was in the opening sequence of Wes Craven's Scream (right) where Drew Barrymore was terrorized and then frankly mistreated by a phone caller who wasn't actually obliged to be in his house at the time he rang her. I still remember the frisson of fear in the cinema audience at the precise moment they realized this.
A more recent effect of the cell phone has been reverberating in Britain in the last couple of weeks. In the 1980s many a demonstration against the Thatcher government curdled into violence between the police and protestors. The police would always blame the protestors, and so would the government, and the tame media would toe the official line, praising our staunch boys in blue and deploring the lefty anarchy of the unwashed streetfighters. The latter would claim a different story, but without much credence.
The 1st April protests in London were different. Again, they curdled into violence; again the police blamed the demonstrators; again the media dutifully (and initially) followed suit. But this time the protestors had cell phones with video cameras in them, and they shot footage of what happened. When Ian Tomlinson (right) died after being struck by a thug dressed as a cop, it was possible to prove what had really happened, and broadcast it on national TV. Political demonstrations will never be the same again.