Justin Bieber From Nowhere

Justin Bieber is 15 years old, from a small town in Canada and definitely having a moment. This particular moment had what felt like a bazillion little girls lined up around the Hard Rock Café in Times Square to catch Justin's performance at the third annual "Tiki Rocks the Square for Children's Miracle Network Hospitals" event in New York.

Madonna and Lady Gaga

A staged - and rather poorly acted - fight between Lady Gaga and Madonna on Saturday Night Live has become an instant YouTube sensation.

The Jay-Z

Shawn Corey Carter, better known by his hip-hop alias Jay-Z, turns 40 in December. In rap terms, the big Four-O is an unheard of milestone. After all, this is a genre where most careers expire in one's 20s, and that's if they manage to avoid getting shot first.

Then again, not every artist -- let alone rapper -- has notched up a staggering record of 10 number one US albums. Amazingly, this puts Jay-Z ahead of Elvis Presley. This weekend's release of his 11th album, The Blueprint 3, should see him catch up with the Beatles.