CBS Radio News is heard by more than 26 million Americans weekly on more than 500 radio stations throughout the United States, with up-to-the minute information -- hourly newscasts, instant coverage of breaking stories, special reports, updates, features, customized reports and news feeds.  Among its many features are "The World News Roundup" and "The World News Roundup -- Late Edition," the longest-running news presentation in the history of broadcasting.  Harvey Nagler is vice president, CBS News Radio, and Constance Lloyd is general manager.