When I fret over which lens to bring with my, I simply waste time staring at my equipment instead of shooting. To ensure that this doesn't happen out in Asia, I will keep my 28mm mounted on my dslr. I will keep my 50mm in my backpack as a reserve. No accessories, flash units, fancy lens hoods, or anything of the sort.
It'll be me and my camera (and whatever food I pick up along the way). If I can't take good pictures with just those things, then clearly I fail as a photographer - because getting more expensive lenses isn't really going to get me anywhere.
See you all in a few weeks.