The all-rounder - the Bivy-Poncho UL by Exped. The Poncho can be used as a rain coat, bivy sack or as a small awning. It can also be used to collect rain water, as an additional sail, as a tent footprint or even an improvised hammock.
The ultralight fabric comes with welded seams, making it completely waterproof. It can also easily be packed away in the breast pocket when not in use.