When the Obama girls, Malia and Sasha, move into the White House, they'll be the latest in a long line of first daughters to enjoy America's most famous residence. As generations have given way to the next, some offered advice to their successors. "Have a helluva good time," Alice Roosevelt Longworth wrote to Susan Ford. LBJ's daughters planted notes in the solarium for Tricia and Julie Nixon to find. One of the biggest perks of the grand digs, according to the Johnsons: a kid gets to be near her hard-working dad.