GPS - Gets us to appointments AND back home.
Each week I make a big pot of soup and freeze it in individual, microwavable servings, so my son can have hot soup whenever he likes.
I also keep bags of organic, frozen fruit in the freezer, so he can always make a smoothie. I buy most of it already frozen, (Costco sells organic frozen fruit at reasonable prices) but I also chop and freeze several bunches of ripe bananas.