The TFWG PowerWorld International Travel Magazine and Website will probably have a special page devoted to nude beaches and clothing optional entertainment.
(Travel Tip: By special request, further information on clothing optional beaches. Apparently, there is a clothing-optional swimming hole outside of Bar Harbor, Main. on Lake Wood. I also found that Bare Buns Family Nudist Club serves nudist families, couples and singles, primarily in the areas of Washington, DC; Baltimore and Annapolis, MD; and Richmond, VA. I know for sure that the Ponderosa Sun Club in Roselawn, Indiana, is located about 50 miles SE of Chicago.)