Those towns in Georgia may be small, but nothing compared to the towns that appear in Wikipedia's List of places with fewer than ten residents.
One of the townships listed under "Places with one resident" is Erving's Location, New Hampshire, which may or may not have one resident.
According to the 2000 census, one person lived in Erving's Location. However, in a recent "Sunday News" New Hampshire newspaper edition (printed on June 27, 2004), Suzan Collins, the Coos County administrator, said the following about Erving's Location: "We're required to do an inventory of property lists and there isn't anyone who is a registered resident. I don't know how the census picks this up." She also said that the only taxable property in Erving's Location are telephone poles. [Link]My great-grandfather's family lived for a time in a nearby township called Cambridge. It just missed the list, having exactly ten residents in 2000.
Also on the list for having one resident is Holy City, California—founded in 1919 by William E. Riker, a cult leader who propounded celibacy for others and bigamy for himself. The tiny town even had its own radio station once.
A radio station offering a variety of programming was built in 1924, and went on the air on July 7 of that year under the call letters KFQU. Though the call letters may appear obscene, they were issued sequentially and could not have been deliberate. The station went off the air in December 1931, and had its license renewal denied on January 11, 1932, due to "irregularities." [Link]This article about Karen Keller of Hibberts Gore, Maine, makes an interesting point: If you're a town's only resident, your personal census data is available for all to see.