Who says iPhones can't replace all musical instruments by the year 2010? This handbell demonstration suggests that at least some classical instruments are dead already.
I love handbell because each person in the row is responsible for just a few notes of a whole song. The Melody Bell iPhone app lets you tune your "bell" to whatever note you need to make the song, but just one note at a time, so you need to get together with friends to make it work, and shake it when your moment in the song comes. (An iPhone in each hand would be cool, though expensive.)
I wouldn't have let that kid get in the way of an otherwise solid performance, but you can see the promise of this, and the sound is damn good. It may not be the first ensemble performance using iPhones, but it's probably the biggest—and most scalable—to date. [Product page and iTunes App Store link]