baseball needs replay

how many baseball games are gonna be called where a obvious Homerun is Missed? the NFL has instant replay and the NBA checks over certain plays, now granted there are still error but overall they get it right. but Baseball is blowing calls for the Long ball left and right. with all the technilogy of today you would think Baseball would step it's game up. with the build in ball parks, funny time strike zone,etc.... you would think they would have things more tighter. it's one thing if something happens every once a blue moon but now it seems like a every other week type of thing.i enjoy watching the game but I always feel that there is gonna be a bad call that can haunt any team. you need something that balances things out.i say place a extra signal on the outfield area so if a ball hits a particular place then it will signal a homerun,etc.. I mean it doesn't make sense for things that the viewing Public can see and the call is missed.a bad call can cost a team so much. yeah one bad call that could have been prevented might cost a team the whole nine.