I can't remember who brought it up, but someone proposed an additional "official" that sits up in a booth, and if there's ever a question of foul/fair, homerun or not, the umps can signal up to check, and the whole process would take less than a minute. Not a big disruption, and on these plays that can have a HUGE impact on a game's outcome, the correct call can be immediately made. I thought it sounded like a fantastic idea.