While checking out the showroom floor at Macworld 2012, we encountered this cute little game called Bag It! The goal is to efficiently bag your groceries while optimizing space and not crushing items by, say, putting a watermelon on top of the bread.
These aren't normal groceries, either. Each item is actually a character that has a personality. Bagging characters next to each other that get along well will help you achieve higher scores. For example, Sunshine the OJ and Spilt the Milk are sweethearts and bagging them next to each other awards an additional 300 points.
If organization isn't your style or you need to blow off some steam, Bag It! also has a Rampage mode where your goal is to actually destroy as much groceries as possible.