Battery Adapter

This could come in useful. How to adapt C batteries into D batteries using quarters via Evil Mad Scientist Laboratories. Just place 2-6 quarters on the battery ends on the spring side of the battery. How many quarters you use depends on how tight the "springs" are.
http://www.evilmadscientist.com/article.php?story=ctodadapter&query=batteries
The little article says it often works but not always.
Clever.
I know I just needed D batteries for something, when I remember what, I'll go try it.