Britney Spears unveiled the sizzling cover photo for her new CD on Friday. She also revealed that her next single will be "Circus." "The song is an up-tempo track," says Spears' official Web site. "It's gonna be absolutely crazy!" "Hit Me Baby" just turned 10 years old! Revisit Spears' best on-screen moments. "Womanizer" is the first single off the singer's sixth album, Circus, which...