Fixed-Width Key Organiserse.g. Lattice, BladeKey Bolt
There's another kind of organiser with a similar design, except the handles are made of a single piece, of fixed width. That means you can only hold a fixed number of keys. I think for sacrificing flexibility, you get a more secure holder; at least you can tighten it without making the keys too stiff to use.
I wish someone would make a spring-loaded one - press a button and your key would flick out, like car keys or knives.
Next, I'm thinking of transferring some tools from my True Utility multitool.