There was a time last July when heat, humidity and time-zone weariness -- along with numerous pat-downs from airport security folks -- had Giants announcer Jon Miller asking himself a serious question. "What am I doing ... do I really need this?" The answer, fortunately for San Francisco baseball fans and Miller aficionados across America, was yes. And now, the man known for his accurate and colorful action descriptions has been given a six-year contract extension through 2012 as the Giants' play-by-play voice on flagship radio station KNBR 680 and on television.