If I'm alone, I usually let out whatever farts I have in store. Partially to avoid identifiably stink up the office around my coworkers, and partially as a gift to the next person taking the elevator.
I rarely travel more than a couple of floors. It's a small building, so chances of being intercepted are low. Besides, I can always pretend like nothing; Remember the famous Benjamin Franklin quote: "He who smelt it dealt it"