Pennyflute is the term that my 11 year old nephew used to refer to a pennywhistle. I thought it was funny.
Pennyflute? 
Hammy Hamilton actually makes something you might call a pennyflute, though it costs a little more than a penny, weighing in at about $50. It’s at
http://homepage.tinet.ie/~hammie/practice.htm
One of these days I’m going to pick up one of these just to see how it does play.
–James
http://www.flutesite.com
Clarke once attempted a transverse flute. There’s a picture on the C&F page about Norman Dannatt’s collection.
I’ve known a music shopkeeper to refer to whistles as “tin flutes.” Whatever you call them, I like the way those things sound. (:
LOL! Along the same line… a neighborhood kid saw me out playing my whistles last summer… when I explained what they were, he got a little mixed up and started calling them “Pickle Whistles”. I thought that was cute!