Vodafone New Zealand has an impressive ad. It features 1000 mobile phones that gradually receive text messages and, with their alarm, recreate Tchaikovsky's 1812 overture. There were 2000 text messages sent and each phone had to be carefully set. It took tremendous amount of work, as one of the producers says: "any adjustment you want to do to the phones, you have to do it a thousand times". The final song is still not perfect, but you can definitely hear the music.
Read more and see the making of on Vodafone NZ