1. Shawl: Those nice, flowery coton shawls have always worked miracles for me. I have tied it around my upper body as a top to swim in Thailand, folded it up to use as a pillow in long distance buses, wrapped it around myself to prevent freezing, used it as a cover to shield myself when changing clothes, sometimes in public, used it as a head scarf, to cover up when entering temples... I neevr go without one!
2. Rubber bands: Handy to tie up my hair (of no use any more), to secure things in place, like socks, underwear, clothes that I have rolled up into tubes to prevent crushing and space saving, keep imp papers together.
3. Duct tape/silver tape : Secure everything, from self-untying shoe laces to tear in mosquito nets, can be used as plaster when you are out of band aids, stick rips in the backpacks, fix wobbly tripods...just about anything. I never go without one.
4. Swiss knife: For just about everything!
5. Headlight: Works better than a torch and leave your arm free