Best of 2007

The 10 Wildest YouTube Stars

From Chocolate Rain to the Dramatic Chipmunk, these are the clips you couldn't help but forward this year. By Cara Lynn Shultz

THE MUSICAL KITTY

When Betsy Alexander is away, Nora the cat will play – her piano. "I didn't teach her how to do it," her owner told the Philadelphia Inquirer. "She really has the personality of a great composer. Maybe she's Beethoven."