Sette Vexx Derailleur Hanger
If you're rolling a DH bike you more than likely have broken and/or bent some stuff in your day. And you're probably aware that a derailleur hanger exists to take one for the team should the need ever arise.
Do yourself a favor and pick up one (or a couple) of these before you actually need it. That way you can be out riding instead of waiting by the door for the Brown Santa to arrive with the little widget you need to get your bike off the DL.