Hello everyone, I've been playing around with T flip-flops and I came up with this.
I haven't seen a smaller design than this anywhere.
It is 4x3x2, and uses 3 repeaters, 4 redstone dusts, and 5 redstone torches.
The output is the torch on the blue block.
Darn, you're right! I have not thought of the mechanical T flip-flop.
I shall change the title to "Most compact redstone T flip-flop (4X3X2)" then =D
No, it's not edge triggered, it will not work if you replace the button with a lever. but it works fine by itself, giving a steady output.
It is still very nice and since a part of it produces a pulse when it switches from off to on so you can use it to make a very efficient binary counter. Also the mechanical T flip-flop doesn't work very well with lag or in smp so can break easily so your design will defiantly be my preferred design for future use.
I haven't get it to work with the 10-tick pulse an button gives. According to my simulations, it would require a 5-8 tick input. But by setting all repeaters to 1, it could accept a pulse at 3 or 4 ticks.
This is the picture of this T-flipflop with a 3-tick edge trigger. The flipflop in itself is in the blue box: (5*5*2)
With this constellation, you can also connect it to other redstone components simply by using another input than a button.
EDIT: maybe I should specify, that I haven't tried this ingame. Only in my simulator.
The first picture needs changing. The Redstone Repeater to the left of the Blue wool block is wrong. For me this setup wouldn't work unless I had that Repeater on setting 4. Maybe it's just my game, I don't know.