Pop star Britney Spears has reportedly granted her approval to husband Kevin Federline's latest money-spinner - hiring himself out. The hapless spouse has been dogged by accusations of "freeloading" in recent months, and has allegedly come up with a novel way of bringing home some cash. The Scoop reports Federline is charging up to $20,000 (GBP11,000) for cameo appearances at soirees and has earned $700,000 (GBP388,888) in the last four months alone.