3rd episode of Stephen Fry on the Phone

http://www.bbc.co.uk/iplayer/episode/b017chq0/Stephen_Fry_on_the_Phone_The_Accidental_Discovery_of_Text/

Stephen Fry meets the men who created the first texting facility, as well as other less commercially successful products like taxifones, payphones on trains and in-car fax machines. He hears how texting triumphed unexpectedly when paging was all the rage, partly because paging services never seemed to work on Friday afternoon. On the earliest handsets there was no way of replying to a text. Later, just in case someone might want to reply, they included a short list of possible pre-set answers: yes, no and later. In the mid 90s texting was just one of countless facilities embedded within the new digital mobile phones: no one thought it that important. Last year alone, a staggering 6.1 trillion text messages were sent. And most of them received a reply.