Ocarina by SMULE, a 99-cent app on the iTunes App Store turns the iPhone into a virtual flute. It is currently one of the best-selling iPhone's apps and has pulled in about $800,000 for SMULE. They also make a buch of other apps like Sonic Lighter, Sonic Boom, Sonic Vox, and Zephyr. The latest the company released is, Leaf Trombone.
SMULE Leaf Trombone