Big ugly good raincoat
Went down to Market St in SF today, and at the cheaper end, I found an awesome army-surplus-slash-cheap-outdoor-gear store called Kaplan's. Got myself a really big, quite ugly, and definitely waterproof poncho, which can cover me and my massive backpack with its vomit-coloured Army-camo protection. For $10, I'm very happy with my purchase, which should keep me dry even in the wettest and most remote corners of South America.
Army raincoat hanging in my dorm room. Don't worry, there's no-one hanging inside it.