The iAno iPhone Piano , now know as Pianist by MooCowMusic is a virtual piano for your iPhone. It was used in the music video made by Atomic Tom where they played their song Take Me Out live on a NY Subway train using nothing but iPhones.
Main features are:-
– 4 Octaves, with a navigation system to move easily between them.
– Uses real piano samples.
– Multi-touch allows up to 5 keys to be pressed at once for complex chords.
– Keys are animated so they look like they are being pressed.
Get it here: 