WASHINGTON (AP) — President Barack Obama's first public act in office Wednesday was to institute new limits on lobbyists in his White House and to freeze the salaries of high-paid aides, in a nod to the country's economic turmoil.Announcing the moves while attending a ceremony in the Eisenhower Executive Office Building to swear in his staff, Obama said the steps "represent a clean break from business as usual."The pay freeze, first reported by The Associated Press, would hold salaries at their current levels for the roughly 100 White House employees who make over $100,000 a year. "Families