Camp camp show.

Here's a interesting gallery of photos taken in WWI prison camps of soldiers dressed up for camp shows. 

U-boat POWs

Here's sometime wartime footage of German POWs doing the "walking round the wire" thing that you always see allied POWs doing in films.  Looks like every nation indulged in that hobby.

Wartime Boxing?

I was astounded to read this article reporting how an RAF pilot escaped an internment camp but was sent back by the British government!

Prisoners of War

Over on the WWII experience web site thay have a collection of short memoirs from POW interned in the Pacific campaigns.