You won't have to pack as much stuff if you pick items that can serve double or triple duty. The olive-colored khakis or black jeans that you wear on day hikes can pass as dress trousers at dinner, if you wear a nice sweater or blazer with them. For women, fashion consultant Mary Stephenson recommends a wrap dress as an all-purpose travel garment for casual and relatively formal occasions [source: Flam]. An oversized T-shirt can double as a nightgown and a beach cover-up. And since every ounce counts, leave your clock-radio at home and wear an inexpensive sports watch with an alarm function to get you up in the morning [source: Lichten].