[Cryptography] Talk on encryption to non-crypto audience ?

[Henry Baker]

I'm going to be giving a technical talk on
crypto to non-crypto people.  These are
scientists & engineers, but not computer
scientists or mathematicians.  They recently
heard about quantum computers, mobile
malware, optical fibers, and a future talk
is on 3D printing, so you get the idea.

Any advice and/or reference links for
such a talk ?

I was thinking of a couple of scenarios --
email/SMS and buying something online.  I
thought I'd talk a little about 1x pads &
Diffie Hellman exchange.  Possibly mention
Bitcoin blockchains.

I'm probably going to ignore Rogaway's
advice re no cute pix.

Any suggestions/recommendations ?

Thx in advance.