It's really quite amazing, and pretty easy to see when you're talking about a single person putting off taking it for a year. But when you get a couple, particularly when both of them have earnings, it can get very complicated.
This article I saw today explains a couple of the issues pretty well:
The author, Scott McLeod, a NAPFA-Registered Financial Advisor, answers a specific question regarding a spouse taking benefits, but in the process, he adds some great information about a couple of strategies:
Some good stuff there.
Also, Larry Kotlikoff has a regular column on pgs.org now about Social Security and related issues. Always worth reading: http://www.pbs.org/newshour/rundown/2012/10/ask-larry-can-a-thirty-something-in-good-health-collect-social-security.html
David S. Meyers, CFP®