For years, Geoffrey Holt was known as a mobile home park groundskeeper in a small New Hampshire town. Now, he's being remembered as a millionaire who gave his fortune to the community. Holt died in June at age 82. His 4,200 fellow residents in the town of Hinsdale recently learned he left nearly $4 million to benefit the following areas: education, health, recreation and culture. Holt was a modest man with few needs, but also a savvy investor who read financial publications. The Connecticut River town that has the nation's oldest continually operating post office plans to use the money frugally, as he did.