Shorter folks could carry one of thesehttp://www.basspro.com/webapp/wcs/st...kEnabled=false
Ive used them before to climb trees for deer hunting, work nice, gets you up a few more feet if needed, add two or three or ten for birds-eye view. Won't damage the tree, required here in Michigan, no screw in style steps are allowed on fed. or state hunting lands.
Or you could carry one of thesehttp://www.rei.com/product/782801
strap it on tree and climb up.