Apple is holding a contest on iTunes called "Countdown to 10 Billion Song Downloads." The user who downloads the 10 billionth song from iTunes will receive a $10,000 gift card from Apple. " iTunes changed the way you buy music, making songs and albums available for download, day or night," Apple said. "Seven years later, we're about to celebrate our biggest milestone for music, yet - 10 billion songs downloaded. Buy a song, and if it's the 10 billionth download,