With the addition of instant replay to the game, I got to thinking, what other things could change about baseball to make it better? 

So my question to you all is, what would you change about the game of baseball?  From the simplest rule change to something huge.  I'm just interested in your thoughts.  Some examples include Al's oft mentioned let the batter appeal to first base on a check swing.  Something a bit larger would be adding more to instant replay.  Or even something relating to umpires variant strike zones.  Or the infamous "technical balk" promoted at one time by a poster here.

Please, please, please:  If your answer is "nothing, the game is perfect" please don't post.  I'm interested in changes you'd make.  However, I don't wish to discourage you from arguing that a potential change may go too far or is a bit out of place (eg  "technical balk").

My change: I'd like to see something implemented to standardize the strikezone somewhat.  I hate how one pitch can be a strike and the next pitch, which is identical, is a ball.  I don't know how to implement it though.  I leave that to those of you who are far more informed than I, which is 90% of you.