Yes! Hard cover books work too. You can smash it down between the seats and under the armrest to create your space.  Other helpful things: -earbuds in case it tries to talk to you -empty water bottle you can refill after security/on the plane and drink while judging its soda -smelly lotion to combat dryness and others' 'travel' smells -cold dead eyes for the fats and sweet smiles for the flight attendants who have to deal with them