Pop princess Britney Spears has swapped her trademark long blonde hair for a dark bob.

The stunning SLAVE 4 U songstress was spotted sporting the dramatic new look as she spent a day out in Manhattan, New York.

One onlooker says, "The new look had a dramatic effect. She walked through the streets of Manhattan and many shoppers were doing a double take.

"Britney definitely looks grungier and raunchier than she ever has before."