Every time I travel with a pipe (which is almost every time I leave my room), I bring a spring-loaded windcap, though I very rarely have one on my pipe while smoking it. Rather, I put it on my pipe when I am going to put it in my pocket, to discourage tobacco or ash from falling out. The downside to this is that a windcap does not fit very well on plateau briar or on a curved rim, making it more likely to slip off while in a pocket.