The 100 arms, legs, abs.

Do just one body part or all three if you're ambitious.

Scene takes place indoors
          .....30 second plank
          .....15 backward leg lifts each side
          .....20 bicycles  

Gun, knife, or other weapon drawn 
          .....10 push ups
          .....20 jumping jacks
          .....10 straight leg lifts

Crying or kissing
          .....15 lateral arm raises
          .....15 forward leg lifts each side
          .....10 reverse crunches

Injury, death, fight scene
          .....15 tricep pushups
          .....20 sumo squats
          .....20 oblique/side crunches each side

Yelling or mechanical tinkering
          .....20 bicep curls
          .....30 calf raises
          .....20 crunches

Noble sacrifice or apology
          .....15 shoulder presses
          .....30 second wall sit
          .....20 Russian twists