The one I'm going to mention here is the Infantino shopping cart cover giveaway. Those carts at the store are usually super gross, and made of hard, cold plastic and metal.
You try sitting on that thing for an extra-long shopping trip. You know which ones I'm talking about? The ones where you go to the store because there is nothing else left in your house except horseradish and a can of BBQ beans and a bad storm is coming and you HAVE to stock up.
Ok, that might only be the case in my house, but you still get my point. You need one of these. More importantly, your poor little baby bum needs one of these. Even those squishy fluffy diapers don't help that much to add to the overall comfort for a trip that long.