Christine Benz, Morningstar's director of personal finance, writes in the linked article:
The bucket approach to retirement planning is straightforward and makes intuitive sense. The basic idea, as envisioned by financial-planning guru Harold Evensky, is that a retiree holds a cash component alongside a well-diversified, long-term portfolio consisting of stocks and bonds. Knowing that money for near-term spending needs (one to two years' worth of living expenses) is parked in cash helps the retiree cope with the fluctuations that will inevitably accompany the stock/bond portfolio.
I have stuff to plant, ferns and things, so I will read the Benz article carefully later. But, I am posting this link so that anyone finding this post can continue along without me.
I might add that I am doing the bucket thing to a certain extent already. I try to keep enough cash on hand in my various RIF accounts to keep my books balanced for the coming 24 months. The goal is to prevent being forced to sell equities at an inopportune time simply to meet financial demands.