I learned how to tie a couple special knots in an arbor rope today so you can climb a rope into a tree.
The knot is tricky at first, but I got the hang of it. It's called a Blake's Hitch. And there's another hitch for your feet to rest in. You sort of inchworm your way up the rope, alternating the knots you slide up while you rest on the other knot.
Kind of cool that I got the rope up there, tied the knots and did the climbing myself in this set of pictures.
A friend took these for me, but only gave me low res copies.