I passed this info on to my father who is much closer to the age where he may be able to take advantage of it, but I wondered if anyone could comment on the viability of the approach described in this article?
As a Certified Financial Planner(TM) certificant, I can confirm that file and suspend is a perfectly viable, legal, and often smart approach to Social Security benefits for married retirees. Dilip is correct that you should check both levels of benefits when both spouses have earnings that were subject to Social Security taxes (either as an employee or self-employed).
The SSA website actually explains this approach on this web page: http://www.ssa.gov/retire2/suspend.htm
I would also add that this can be a sound strategy for single individuals as well. For example, let's say a single person has enough assets or other retirement payments to live on for a while, so they don't need their SS benefits right away. Instead of just waiting to file at age 70, they could file and suspend at their full retirement age. This may be a good idea because the SSA allows you to reinstate your benefits at any time and receive all the benefits you didn't receive from the time you filed and suspended. So if our hypothetical person finds out they have a terminal illness, they could have their benefits reinstated and collect a lump sum of benefits that would have been paid up to that date. In this way, it acts as a mini insurance policy. Granted, it's of limited use, but it's not a bad idea if you can manage without the payments for a few years.
AARP offers a handy calculator that will suggest the file and suspend strategy if it makes sense: http://www.aarp.org/work/social-security/social-security-benefits-calculator/ However, I would recommend consulting with an expert to make sure there aren't any aspects you're overlooking before doing this. I'd look for a fee-only, hourly financial planner for this sort of project.