Rigging a dog's foreleg

After struggling to find a good way for rigging a dog's foreleg I came up with a solution that I wanted to share with you. I haven't been animating this rig yet, so I don't know if it really is as efficient as I thought it would be. So this is most likely not an ideal rig, still I thought that some of you maybe can find this techniques useful. Comments&Critique more than welcome! :-)

Credits go to Tob, who did an excellent foot rigging tutorial on Youtube (http://www.youtube.com/watch?v=tApdSx_4b0Q), that I highly recommend to anyone doing rigs in blender 2.5. I learned a lot from his videos.