In addition to my shelter, I like to carry a cuben 8.5x11 tarp (which many folks use as a shelter) if I know I'm going out in sustained rain. I can use the tarp during the day set up in a modified lean-to for a nice lunch break without having to break out my main shelter, and it'll accomodate 2-3 people easily for such a use. It's incredibly light, so I'm not adding that much weight. Also makes a nice dinner area for 2-3 so we can eat together instead of each retreating to our shelters for dinner.