This is a very useful invention indeed only if the keyboard touch feels a lot like the real thing. I play my grand piano while listening to the music I want to transcribe on iPhone ear-piece. Piano Silhouette is a sort of combination of the two. How good is it?
The Piano Silhouette is 12 centimeters long, 4.5 centimeters wide, and features a rechargeable battery. The USB port facilitates data transfer and charging operations, while the small LCD below the touch controls provides feedback to the user.
Check out this design by Jia Peng
Piano Silhouette - MP3 player with a portable roll-out piano.