Celebrity News: Click Here to See What's on Barack Obama's iPod

The Democratic presidential hopeful spills all to Rolling Stone

Celebrity News: Listen to Rihanna's New Single

She debuted the ballad, "Take a Bow," on Friday

Celebrity News: Jessica Simpson: Why I'm Recording a Country Album

The singer also says she is uncertain whether she'll tour this year

Celebrity News: Hot Stuff: Madonna Makes it Into Rock's Hall of Fame

After a 25-year career, she will be inducted into the hall, along with John Mellencamp, next March

Celebrity News: Carrie Underwood Tops American Music Awards, Wins Favorite Female Artist, Favorite Album

Click here for a complete list of Sunday night's winners