Christy P showed me (via technology, not in person) a new way to tie a back carry, just in time for some serious hiking with my not-yet-sitting-up four month old. Check it out — photos at the link and a link there to some Youtubitude.
I wore Leo for a few hours the other day, very comfortably. Mark hiked with Leo on his back for a family hike today. Worked great. Much of the weight seems to be distributed onto my abdomen and ribcage.