auditory feedback

So I worked with this kid this week who COULD NOT HEAR HIMSELF PRODUCE /r/ INCORRECTLY... 

I whipped out my iPhone and pulled up the Voice Memo app. I recorded his production of /r/ in the initial position of words in sentences. When I played back his recording, his eye grew big and he quietly said "oh."

BREAKTHROUGH!!!

if you were on a deserted island...

If you were on a deserted island and could only bring ONE item to use for speech therapy, what would it be?  

THIS book- I would bring this book-  it is super versatile and can cover just about any speech, language or fluency goal out there.  I've used it so much that the binding is coming off... I hope I can find a new one at the conference I am attending this week!

What's the ONE item you can't do speech therapy without?