A federal court on Thursday tossed out a lawsuit to block the city of San Francisco from renaming a playground after native son Joe DiMaggio, rebuffing the lawyer for the Yankee Clipper's estate -- who claimed the honor was insulting. The city is said to be prepared to spend $6 million to refurbish a small park and name it for the Yankee Hall of Famer, who died last year at the age of 84. Also on Thursday, a $4 million playground in London named after the late Princess Diana opened for business -- or, rather, for swordplay. The very large sandbox contains a replica of Capt. Hook's ship from "Peter Pan," one of Diana's favorite stories. Besides the many children who gathered to celebrate the opening, Diana's brother, Earl Spencer, was her one family member in attendance.