A Poncho is a very useful item, it is both clothing and shelter. It can protect you from the rain and snow while on the move or be converted for shelter duty as a makeshift tarp. A good poncho should be lightweight, durable, cover as much of you body as possible, and have points to tie it down when functioning as a shelter.
Poncho as Shelter
A liner can also be added to a poncho to make it warmer.