The Eisenhower Historical Site (also known as the the Eisenhower Farm) holds a WWII encampment every year. The event features both Allied and German military reenactors, camps, equipment, demonstrations, and speakers, all open to the public. In addition, on the evening of the first day, there is a USO-style dance with a 40's era band.
I'm just glad I didn't have to lug around a 40's era newspaper camera to take my photos -- although a 35-mm Leica might have been fun (with a digital back). Being a swing dance fan myself, I couldn't help wanting to break in and dance with a few of the army nurses and USO girls.