You can see some of these at the online Whistle Museum
Keeping with my theme of liking things that have dual purposes (like gadget canes and vesta cases) here are some whistles, some of which have multiple functions. Pretty cool.
Bullet case whistle.
I like this one. It looks sturdy and is probably a good heavy weight.
Here's onw in silver and enamal. I like this one and also think it would look good if the main body was made from a dark exoitc wood. Maybe I will make one.