When my neighbor passed away, I brought over a lot of the 2 liters I got from the Coke olympics promo, along with glasses and ice. I almost forgot about the glasses and went back with them! It was great to have that on hand so as soon as I saw lots of cars there, I was able to take it over.
Another thing I like to do if I bring food is bring something they can put in the freezer like a pan of lasagna. That way if they have too much food, they can put it in the freezer and use it down the road, or they can pop it in the oven right away if they want. I once a month cook, so I have food in the freezer. It is also great if you have a friend in the hospital or has a baby, you can bring them a meal right away.