If you loosley cradle the Camera with your arms and do a backward role the camera should be adequatly protected; your back takes the hit and yor body protects.
Just remember to take the squeeze off your ears and adequatly control your decent (even if it's a fast decent).... might sound obvious, but if your worried about your new camera and trying to drop quickly before you know it you don't have enough hand to equalise ears and add air to stab!
Check out our cub trip pics from Protea along with the trip report on
http://www.cadsac.co.uk/southAfricaAug2002.htm