Careful what you ask for

Now that the furor has quited a bit over umpire Jim Joyce's awful call that cost Detroit Tigers pitcher Armando Galarraga a perfect game Wednesday night, the calls for quick action on establishing expanded instant replay are growing.
Any reasonable fan who has seen the replay of the blown call can't help but think this whole issue could have been avoided if there was a system in place to allow for review of close plays.
Of course, had there been we would have all missed the greatest exhibition of class we've seen in sports for a long time. I don't know about you, but I will remember the way Galarraga and Joyce conducted themselves immediately after the call and in the hours that followed, much longer than I would have ever remembered a perfect game.
But back to the replay thing.
There really is no need to discuss whether baseball should use replay. It already does on matters of questionable home runs and on fair/foul calls. The latter is especially needed at the Mets new home, Citi Field, which for some reason has ridiculously short foul(fair?) poles.
But how far should it expand?
Many people already complain about the slow pace of baseball games. Adding replay without strict limitations will only add to that problem.
I think I'd go with a variation of the National Football League's rules. First, give managers a very limited amount of challenges to umpires' calls -- one or at maximum two per game.
In football, a coach has incentive to tread carefully, because if a call is not overturned, he loses a time out. There are no time out limitations in baseball, so perhaps if a manager loses on a first appeal, he could automatically forfeit his second one.
Of course, if a manager uses his challenges early, than he might not be able to challenge the bad call on the 27th out of a perfect game.
So perhaps there could be a provision for booth review in the ninth inning, regardless of previous challenges.
You can't let replay overcome the game. I'd limit expanded review to plays at bases and catches or traps. Managers are automatically ejected now if they argue balls and strikes, so there can be no place for review on those calls. And check swings should also be unreviewable.
Just a few thoughts from a baseball fan, who, by the way, is very happy Commissioner Bud Selig did not overturn Joyce's incorrect decision.
That, unlike Joyce's, was the right call.