If I had years to work on it, and the inclination to work that long on such a thing, I would SO make a tree like this:
Yep, that's totally knitted!
I have seen some Christmas trees and other little trees on ravelry, and they are often super cute, but they are miniatures. How cool would it be to have a life-size knitted tree? Beats my plastic one any day!
Find these trees on Ravelry.com: 1, 2, and 3