WASHINGTON (Reuters) - Radio shock jock Howard Stern, who is moving to satellite radio to avoid broadcast decency rules, traded verbal jabs on air with Federal Communications Commission (news - web sites) Chairman Michael Powell on Tuesday, charging him with nepotism and undermining free speech. "It is apparent to most of us in broadcasting that your father got you your job," said Stern, who called in while Powell was being interviewed on San Francisco's KGO-AM 810. Powell shot back that his father, Secretary of State Colin Powell (news - web sites), had nothing to do with his appointment. The FCC...