Gizmodo notices the ancient world:
Since Gizmodo ties this image to Facebook, I guess the Greeks must have been addicted to MySpace:
… and of course, the Greeks were already dealing with the problems of students texting in class:
Techy Romans
quidquid bene dictum est ab ullo, meum est
rogueclassicism 
Given the sartorial condition of the student in the final scene, I suspect this is prima facie evidence that “sexting” was prevalent among Attic adolescents. The young are always descending further into depravity. Read the columns of Hesiod if you don’t believe me.