Mary Hunt is a self-avowed reformed spendthrift and credit-card junkie. When she and her family of four found themselves $100,000 in debt and her husband suddenly lost his job, it was time to tighten the belt. Refusing to sacrifice her quality of life, Ms. Hunt systematically put to work every tip, trick and technique to turn her financial disaster around. Translating that experience into her immensely popular newsletter, "The Cheapskate Monthly,...