Truckers knot sounds like a great idea.
As for the backbone, I'm debating it. I used a monkey hut with a PVC backbone last year and didn't like the design. Our hut last year was based on Love's Monkey hut, which splits the backbone into 3 sections that connect using T/X connectors and duct tape over the ends which wedge into the connectors. Ugh, so crappy. We ended up duct taping the whole thing together so the sections would stop falling out of the connectors.
For a recent regional burn (Euphoria in Georgia) I modified the design to use a single piece of 1" PVC across the top of the ribs, and duct taped it diagonally in both directions.
From what I can tell the only purpose of the backbone/ridge pole that runs lengthwise is to keep the spacing of your ribs consistent.
My thought now is this (basically what is shown in the pic I linked above):
1. Lay the ribs say 4 feet apart, then tie the strap around each rib (thus preventing them from going more than 4' apart). I would do this with 2 ropes/straps about 3 feet on either side of center. Here's an ugly text diagram of one of the ropes (rib, rope, rib, rope, etc.): |--|--|--|.
2. The ends of the rope extend out from the hut and anchor to the rebar staple on the ground, which will pull the ribs apart to their maximum 4' distance from eachother.
Since this relies entirely on the strapping to provide its strength, obviously I'm concerned about getting that right. I'll be bringing some extra PVC just in case, but I don't see what I lose by not having the backbone. Perhaps if I had 3 ridge poles (1 middle, and 1 on either side), the benefit would be that it prevents the hut from twisting? Maybe that's the thought.... Anyway, now I'm getting deep into the Structure side, so maybe they'll end up moving this thread.
Won't have a chance to try it ahead of time since I live in Atlanta, so I do want to err on the safer side