Quarter, then debone here for backpacking.
If I can walk horses to a bull, I just quarter, and leave the bone in to provide structure in the panniers.
I will only bone them out if it's going to be a pack from hell. The leg bones give the meat some shape and it is easier to lash them to your external pack frame (if that's what you use).
Never shot an elk, but I might go this route when I do shoot one.
http://www.youtube.com/watch?v=DYfybuL442w
http://www.youtube.com/watch?v=XmCPtlwXKZQ