I always have several football players in each physics class, or at least students who have seen a football game.  When I teach momentum, a real life example I use is when a large running back is running with the football.  We have all seen a running back continuing down the field with 2 or 3 defensive players hanging on to him.  His momentum is such that those defensive players are unable stop him right away because their momentum before the collision was either zero because they were standing still, or much smaller since they were moving towards the running back at a slower speed.