Keep the teapot on the other side of the room.
Instead of making a left turn, make three right turns. You will burn three times the calories turning the steering wheel, to say nothing of applying pressure to the brake and accelerator alternately.
If your office is on the third floor, instead of taking the elevator all the way up, change elevators on the second floor.
Sneeze. Sneezing uses many otherwise idle muscles in the upper body. Alternate hands when you cover your mouth, so as to exercise your arms evenly.
Prefer comedies to dramas on television. Laughing uses many of the same muscles exercised by sneezing.
Instead of large chips, eat chips of the smallest size you can find, and eat them one at a time. You will raise your hand to your mouth two or three times as often, burning calories each time. Popcorn is an excellent snack for this sort of exercise.
Train your dog to be in the way, so as to prevent walking from one place to another in a straight line. This is one of the easiest tasks for a dog to learn.
Yell a lot. Yelling burns much more energy than ordinary talking.
Find a popular text on ergonomics that shows how to arrange your workspace to make everything you do as easy and efficient as possible. Then do the opposite of what the book says.