As a sound gag they can be very funny. If you can make a deck of cards or a sponge ball squeak and your volunteer can't think of the fun you can have. It can also be used for a running gag. They are inexpensive and have so many applications. Keep an extra with you at all times while performing as they can break and you will need a spare. Lots of potential for fun with these.

I do close up magic and I use squeakers as a gag or just to add sound to my routines. These squeakers are small and their shape makes them very easy to classic palm. If you have seen David Williamson's Cups and balls or Eugene Burger's sponge ball routine you should know how much fun you can have with this.