Everyone who does anything outside—skiing, surfing, biking, camping, kayaking, climbing—should have one of these in the trunk. (We like it because we’re tired of wrestling our kids into ski boots while they balance precariously on one foot in the snowy parking lot.) It folds up so the dirty side is always on the inside, a carabiner attaches to a backpack, and it’s insulated so your feet don't get cold. (Race gatekeepers: take note.) Qwickstand is $15, shipped to your door.