Recently, Vodaphone NZ commissioned a production house to recreate Tchaikovsky's 1812 Overture, using only Nokia cell phones--and the results are extreeemely well-done. In all, the installation required 1,000 cell phones, 52 ringtones, and 2,000 sent messages. (My favorite part---the cell phone vibrating on the snare drum, towards the end.)
It's not actually all that original--Improv Everywhere once did a cell-phone symphony. And the idea of a distributed "orchestra" is at least as old as the mid-1990s, when the Flaming Lips once handed out dozens of cassette players among an audience, so they could "play" various parts of a song. (The Lips also released Zaireeka in 1997, whose eight songs were split into four discs, each containing unique stereo tracks that, when played together, added up to complete songs.) Since then, the idea keeps evolving. For example, the recent YouTube Symphony and the Stanford Mobile Phone Orchestra.