I'd wager one of my Kobold Slaves' soulstones that this has been done elsewhere, but I'd like to be able to attach hotbars together. That way my OCD brethren (both diagnosed and attitudinal) and I can have everything line up perfectly equal. I do not believe there is a way to do this, and if there is I will gladly eat my foot, but I always get frustrated when I cannot line up my bars to pixelated perfection.
On an unrelated note, I would like to have a cheese helmet implemented.