Not the most obvious traveling accessory, but one of the best packing hacks out there: sponges! And no, not for cleaning the hotel bathroom. As ice packs, gel packs, and other frozen liquids are well and truly forbidden by most airport authorities, a smart way to bring along food for the journey, cold drinks, or snacks for the kids, is to pack them among frozen sponges. Lightweight and no hassle from security!
Picture the envy of fellow travelers when you pull out your plane picnic of cheese, bread, and wine for the journey!