Lt. Gen. Thomas Kelly retired from the Army Friday but not without enduring some jibes for the celebrity he attained as a Pentagon spokesman during the Persian Gulf war. "We weren't sure that he would be able to fit us in," said Gen. Colin Powell, chairman of the Joint Chiefs of Staff. "But he did. And, Mr. Secretary, I want you to know we got the government rate - it's only going to cost us $10,000." Kelly, 58, is moving into what promises to be a lucrative career as a speaker and businessman. "Coming to the end of the trail is a bummer, but we all have to go through that," Kelly, choked with emotion, told the gathering in the Pentagon's Hall of Heroes.