Disposable message recorder

Here's another thing I would like to see. I would love to have a post-it note like device that recorded short, digital recordings. Imagine being able to stick a small piece of paper onto something, squeeze a corner of the paper and then record a short message. Another person would later squeeze the same paper to hear the message. If the device was cheap enough to be disposable, it would be a much better way to leave messages then writing.