In the days before the Cintiq and tablet PC, there was the Magna Doodle. This was probably my favorite toy when I was a child. Even though I'd eventually have to erase my drawings, there was something really cool about creating images with a stylus and magnetic particles.
One of my earliest memories about drawing involves trying to draw the Little Mermaid on model with my Magna Doodle (I believed I used the VHS box for reference). I was around 5 years old and I obviously lacked the drawing ability and probably the overall motor skills to sketch a proper Ariel, but I was really determined. After something like 3 hours of drawing and redrawing terrible attempts at Ariel, I went kind of bonkers...
It's been years since that day, but it is STILL pretty damn hard to draw Ariel on model.
Edit: Hahaha...Thanks for this link Mr. Woodside:
2 hours ago