Instant Replay in Baseball?!

It's time that people in baseball stop letting tradition ruin the game. Now, I'm all for recognizing baseball traditions; even more so in baseball than any other sport. But there's no sense in keeping out technological advancements because they didn't have it 120 years ago. Last night alone, there were two plays that cleary showed the need for instant replay in baseball; or at least some level of video review. In Detroit, a huge divisional match up between the Tigers and Cleveland Indians saw the Indians win by one run in extra innings. But the big play was in the 5th. Carlos Guillen singled with the bases loaded and Placido Polanco scored easily, but Gary Sheffield was called out sliding home. Now the play was very close, but why make the umpire make such a difficult call in a close game without the aid of any replay; replay which the rest of the world watching the game on TV has the benefit of seeing. Would the Tigers have won the game if they had been credited with that extra run in the fifth? Nobody can answer that, but why should the game be left with that question when the technology is readily available to assist in eliminating those questions.
While the game in Detroit is only left in question because of a tough call by the umpire, the game between the Phillies and Astros in Houston was simply blown because of a tough call. The situation: The Phils were winning by run in the bottom of the ninth, but the Astros had the bases loaded with only one out. The Phils desperately need a double play. What happens next? Nothing other than a ground ball to shortstop Jimmy Rollins. Right from the beginning it looked like a textbook double play. However, first base umpire Lance Barksdale ruled that Chase Utley's throw relay to first was not in time and the run scored, tying the game at four. Now, yes, it was a close call at first, but not nearly as close as, say, the play in Detroit. And replay cleary showed the ball arriving with in Ryan Howard's glove with "plenty" of time to spare. Simply put, the game should have been over right there; the Phils being 4-3 winners. However, instead, the game heads to extra innings, and the 'Stros win it with a walk-off homer by Hunter Pence in the bottom of the thirteenth.
Now, baseball does not need replay to review every close play and every close ball and strike, but there are numerous close plays every night that could, or do, have an impact on the outcome of the game. How do they determine which are the "big" plays that require replay? Beats me, I'm not smart enough to firgure that one out. But I am smart enough to see that too many games are decided by a human being judging differences of fractions of a second with nothing but the naked eye and ear. These ball players work too hard to see the game turn on a single play all because the league, and traditional fans, feel that instant replay would somehow damage the purity of the game. And I'm not even going to go into how steroids have done nothing to damage the purity of the game