My favorite TI graphing calculator story to tell was back in Algebra II class in high school, while studying polynomial expansion, I wrote a program on my TI-85 that would not only solve them, but also showed the work, so I literally only had to copy the exact output of the program and it looked exactly like I had done it by hand. I asked the teacher if using it would be cheating, and she said "If you know the material so well that you can write a program that actually shows the work, then you're going to ace the test anyway, so go ahead and use it, just don't share it with any of your friends."

The joke was on her, of course, because I didn't have any friends. :-(

Later I wrote a basic ray tracer for my TI-89. I even made it do 4x anti-aliasing by rendering the scene 4 times with the camera angle slightly moved and had a program that would rapidly move between the 4 rendered pics so that pixels that were dark for only some of the pictures would appear grey because of the screen's insanely slow response time. A basic "reflective sphere over a checkered plane" in that super low TI-89 resolution still took like 90 minutes and drained half the battery.