A computer-implemented method comprising receiving, at a tablet display unit of a first tablet that is coupled to a host computer, image data representing a selected portion of a common display file that is stored on an administrator computer; displaying the image data on a stroke-sensitive display of the tablet display unit; receiving user input from the stroke-sensitive display of the tablet display unit and representing handwritten strokes; transmitting the user input to the administrator computer; receiving, from the administrator computer, second image data representing strokes that other users have applied to the same image data using other tablets that are coupled to the administrator computer over a network; displaying, on the stroke-sensitive display, the second image data; storing, in a memory of the tablet display unit, a data file based at least upon the user input and the image data.