I'm planning on trying this myself, although I have never actually done it before. I plant to use bamboos to make an A-frame around each of my 7 plants, then lash smaller sticks to these at intervals to keep the branches propped up. Last year I had a monster stand of green beans with very big (= heavy) yields on the same bamboos, and they were rock-solid. Also, mine were only 1/2 inch diameter, so the ones you have should be plenty strong!

Let me know how it works out for you, we can compare notes.

If Soemone else has done this before, I'd love to know what they did.

plantslayer, I saw the guys at North Hill Garden doing bamboo A-frames for their tomato in one of their books. Basically each pair of bamboo is tied together at the top, then they are lined up with a single bamboo pole stacked on top. Then each bamboo has a tomato planted near its foot and the tomato plant grows up the bamboo. That is what I was thinking of doing.

How far did you sink your bamboo into the ground? Was it difficult?

I don't think we put the bamboo in the ground more than six inches, if that. We did an A-frame like the one you described, with a single bamboo running across the top, but I am not sure how they would train tomatoes to climb up that... Did they attach something like a grid to the outside of the frame?

Looks like they just tied them to the bamboo but I am not 100% sure of that. The photo in the book was not very large. I don't think you can really train tomato up a support like a vine. I always had to use some of ties.

I grew tomatoes last season using the A-frame method, with a single pole running across the top of the frames.
The structure was 10 feet long with supports spaced at 24"....I grew twelve plants on this structure.
I thought it worked very well although the entire structure became a thicket by mid-August. The plants were healthy and productive, and easily reached beyond the 7-ft. height of the frame.
I trained them up the structure by periodically tying the vines to the poles loosely with parachute cord.
The poles were only pushed about 4"-5" into the ground. One key to keeping everything from leaning over was to make sure the A-frame was firmly bound at the tips, and that the lateral cross piece was firmly bound at each A-frame junction.
I would highly recommend this method, especially if your space is limited.

miket_pdx, so glad to talk to someone that has done it this way before!! So I have a couple of questions. First is how did you construct it? Did you tie them at the top first and the push the ends into the ground, or the other way around? Secondly, did you plant one tomato at the foot of each bamboo and have them grow toward the middle? If so, is plants shading each other a problem at all? Lastly, what did you use to bound your bamboo together?

I tied up two of the A-frames (for the ends) and attached the cross piece to those and got them buried to a depth I liked. (It takes two people to do it this way....the structure isn't stable until some of the remaining A-frames are attached.)
I then tied up the remaining A-frames and installed them along the length of the structure, pushing them into the ground so they just touched the top cross piece.
I used stout twine to bind the tips together, and zip ties to attach the top piece to the A-frames. Once it's all assembled it's very stable so long as all the bindings are tight.
I planted one tomato at the base of each bamboo pole, on the inside. Don't know if it would make any difference where you plant relative to the pole, but I assumed it would be easier to train them this way. It worked fine. The plants become so bushy that I doubt if it matters much where you plant relative to the support poles.
No noticeable problems from shading or crowding, although like I mentioned it became a thicket. Tying or pruning errant branches was necessary to get it trained, but I pretty much let it go its own way after the plants reached the top.

Something i tried last year which worked pretty well was an inverted A frame using the bamboo and twine to circle the plants in all the way up

I went out this morning and set up the first bed with the bamboo support following miket_pdx's direction. Fingers crossed! Once the tomatoes are in, I will take photos and post them here.

I used bamboo as stakes a few years ago. I used three per plant, and pruned each plant to three main growing stems, removing all suckers. It worked pretty well but I ended up going to back to cages.

ikea looks like you knew the answer even before you asked .way to go

I am thinking about trying franki's approach with 3 bamboo stakes per plant too as an experiment. I wonder if there is better or worse tomatoes for this approach. I assume this may not be enough for sungold or cherry type with no pruning whatsoever.