One's a little round, the other's a little . . . well . . . little. They read the news, they engage in limericks, puns and tongue twisters. The little one rambles a bit. They do sketches. They sing. From time to time, they dress in dresses. Oh, and they have the same first name. They're Ronnie Corbett and Ronnie Barker, stars of the long running British variety series that bears their names.