Travel socks make excellent cases for your sunglasses, for small souvenirs, as a makeshift screen cleaner, and as slippers. Have a bug bite? Use that tiny bar of soap from the hotel, wet it a little, and rub it on the bite. Then, take the bar with you to take the itch out of that bite later in the day. Did your shoes end up with water or salt stains during the day and you need to wear them again at night? Try rubbing a small amount of liquid shampoo on your shoes. Just a small amount rubbed in circles with a clean cloth can do wonders.