This year I've had two instances of a team trying to stall things with the clock ticking down, over the course of about 50 timed tournament games.
In the first one, with just a couple of minutes left the defensive coach asked for a conference with his pitcher. He had conferences left and the umpire has no right to deny them if he does. Opposing coach starts going ballistic, screaming about how they were delaying the game.
While an umpire can't deny an otherwise legal conference, he can control the length of it. Based on the clock situation, I probably allowed about half as much time for this one as I normally would. Let them have their meeting, then headed out to the circle to break it up.
If it was a stalling strategy, it backfired! The inning ended with about thirty seconds left on the clock, so we had to play another inning anyway. Neither team scored in the last inning, so we ended with the same result we had the prior inning.
The second incident involved a sudden rash of shoe lace problems for the defensive team! First, the pitcher asked for time to tie her shoe. She was taking time with it, so I stepped out from behind the plate and said, "Speed it up, Pitch, let's go!".
A couple of pitches later, suddenly the shortstop is having problems with her laces. This one got a more stern, "Knock it off and let's play ball!", in my grumpiest mean old umpire voice! Neither "shoe lace problem" benefited the defensive team and the game came to it's natural conclusion (well, as natural as you can get when using a clock while playing a game designed to not use one and not lasting a full seven innings...).