The doubleheader is an ancient relic on today's sporting scene,gone the way of pay telephones and the manual typewriter. Once astaple of Sunday afternoons, it no longer appeals to players,executives or even the majority of fans. It does exist, though, with a little imagination. On Monday inthe Cactus League, the A's day and the Giants night each played games intheir home ballparks. A few observations on how this Bay Areaextravaganza went down: