Bernadette: Get that guy! Get that guy! Pew! Pew! Pew! Pew!
Sheldon: Dr. Rostenkowski, it may interest you to know that saying pew, pew, pew isn't as effective as pressing your blaster key. In the same way that saying whee doesn't make the land speeder go.
Bernadette: (aiming at Sheldon) Pew!