A line of LEDs shooting into small fibre optics arraged into a line could be driven by a PIC to print text in a similar manner to "POV toys"
These things work on persistence of vision, and basically flash out a message on one line of LEDs. As you swish them through the air, their message appears, courtesy of the persistence in your eye.
The same trick would work with film. If you really wanted to be complex, you could hook the clock input of the PIC to the speed of the film - I doubt this would be necessary though...