How to convey how much computing power has grown since the 1960s?
This is really difficult to communicate to anyone who hasn't lived through it (and even to those of us who have).

I don't usually go back as far as the 60s.  I show my students a picture of the ASCI RED supercomputer from ~1998, which was the first supercomputer to be able to perform 1 trillion floating point operations in a second (1 TFLOP).  It's basically the size of a warehouse floor, with another floor consumed by its climate control system. It cost ~46 million dollars.

Then I show my students a picture of a typical rack of servers from 2008, which could perform 2-4 TFLOPs.  In a decade, the size had shrunk from a warehouse to a single rack, the computing power had doubled, and the cost was about $200K.

Finally, I show my students a picture of a Nvidia K80 GPU card, which can perform over 2 TFLOPs.  In less than a decade, the form factor has shrunk to a card you can put inside a desktop computer, with the same power. Launch price was about $5K. 

That is in less than 20 years.  Extrapolating from that back another 20 years only gets you to 1978; you have to go 10 years beyond that to reach 1968.  It's really hard to communicate the extent of this change.

And that's just the change in raw computational power, ignoring other advances like the Internet...