As soon as I saw this a few months ago, I started saving up my TP rolls.
I used the glue/clothes pin method (as opposed to the staple method) with some old "school glue" I had. I had to do the project over a few days, due to my number of clothes pins. When the glue was all dry, I spray painted it green. For now, I've hung it up on one wall of my living/dining room, though I feel like it looks out of scale with the wall and am thinking of where else to put it in my house.
A great, easy, CHEAP project. :)