No. 10: Miley Cyrus
Birthdate: November 23, 1992 (age 17)
Why She's Hot: She was cast as Hannah Montana at age 12, and when the show premiered to the Disney Channel's largest audience ever, Cyrus was an instant teen idol. The "Hannah Montana" franchise has spawned four seasons, a string of hit singles, a full-length movie and enough branded merchandise to fill up a middle school gymnasium. Cyrus' ascent toward adult famedom ramped up earlier this year, when she released a more mature-sounding album, "Can't Be Tamed" in June. The album didn't quite tame the charts though, and Miley appears to be focusing more on her acting career with three films ("LOL: Laughing Outloud," "Wake" and "Wings") in the works. Still, we don't expect the unflappable Miss Cyrus to stay away from the record studio for too long.