Curling:

During the match after you or your opponent has 
thrown the stone, pressing the "Z" button will 
speed up the process.

If your opponent lands a stone in the target, 
aim for it during your turn. The opponent's stone
will bounce out and yours might even stay in.

When playing against the CPU, you can control the
speed of the CPU stone by using A and B like you
control your own stone.