You are correct, technically, but the real value of these kind of two-factor authentication techniques is that they are immune to replay attacks. Someone listening in to the Apple login process can't re-use the transmitted SMS code, because Apple expects to see a different code each time you log in.

See if you pick up some of the interface technologies for the equipment you're already familiar with: UPS, ATS, Air Conditioner, Generator, PDU, remote sensors. Most modern infrastructure like this has hooks for SNMP or Modbus, and few vendors (even the folks who manufacture these items) know what to do with these, or even what *can* be done with them. If you can also pick up an open source monitoring system like Nagios, and some basic networking, and a bit of Perl, you can put together inexpensive infrastructure monitoring. If you can talk your current employer into letting you play around with this stuff, then you both win, and you are doing fun stuff that is less physically demanding.

Ham Radio is a great hobby for someone like your dad. There are technical, social, competitive, and public service aspects to it, and there are so many areas of interest within the hobby that any technical person can find one or more things to pursue. Check out the information and publications at the ARRL (arrl.org) web site.

Check out Norsam's HD Rosetta product (http://www.norsam.com/hdrosetta.htm). An inert nickel plate, etched with a focused ion beam. It's supposed to last 1,000 years, and it's readable with a microscope.