The year 2006 was full of momentous occasions. The U.S. population cracked the 300 million mark, Walt Disney bought Pixar and a fledgling Facebook opened its registration to anyone over 13 with an email address. It wasn't a banner year for Pluto, which got downgraded from a full-fledged planet to a lowly "dwarf planet." But good times were in store for a young Miley Cyrus, who debuted as "Hannah Montana" on Disney Channel. Watch her original audition.