VoluntarySimplicity, by DuaneElgin. ISBN ???
I enjoyed reading it, although it seemed a little abstract. YourMoneyOrYourLife is probably a better book.
But, as to why this came up - "Marketplace" was on the radio the other day, and they were doing a piece about the "VoluntarySimplicityMovement". It struck me that voluntary simplicity has values in common with extreme programming -- YouArentGonnaNeedIt, most obviously, but perhaps also OnceAndOnlyOnce and DoTheSimplestThingThatCouldPossiblyWork.
Do your UnitTests fail in the morning? Need help ReFactor-ing your life? Well, at the ExtremeLiving training school, we can help...!
-- BillTrost