Why text messages are limited to 160 characters | Technology | Los Angeles Times
http://latimesblogs.latimes.com/technology/2009/05/invented-text-messaging.html

As he went along, Hillebrand counted the number of letters, numbers, punctuation marks and spaces on the page. Each blurb ran on for a line or two and nearly always clocked in under 160 characters.

Los Angeles Times article about the history of SMS text messaging

Alone in a room in his home in Bonn, Germany, Friedhelm Hillebrand sat at his typewriter, tapping out random sentences and questions on a sheet of paper. As he went along, Hillebrand counted the number of letters, numbers, punctuation marks and spaces on the page. Each blurb ran on for a line or two and nearly always clocked in under 160 characters. That became Hillebrand's magic number -- and set the standard for one of today's most popular forms of digital communication: text messaging. "This is perfectly sufficient," he recalled thinking during that epiphany of 1985, when he was 45 years old. "Perfectly sufficient." The communications researcher and a dozen others had been laying out the plans to standardize a technology that would allow cellphones to transmit and display text messages. Because of tight bandwidth constraints of the wireless networks at the time -- which were mostly used for car phones -- each message would have to be as short as possible. Before his typewriter

aditya: Why 160 characters for an SMS? — http://tinyurl.com/cjwh7x

Quá! Eu sabia que tinha que ter um alemão entediado envolvido...