Split keyboards and how to build them

Article note: I can't encourage people who spend a lot of time at a computer (...which is everyone these days) to be mindful, try things, and customize their computing environment enough. I have a rather large (...and kind of expensive) collection of input devices I've bought or built over the years, and while I don't regularly use many of them, I've learned things about how to interact with computers and use my hands from every single one, and do use a couple essentially every day. I _personally_ don't generally like modal (layered) keyboards for the same reasons I don't like modality in software (hidden state = cognitive load), and I don't love alternative layouts on standard keyboards for the same reasons I don't do super-botique software environments (you'll have to deal with qwerty and WIMP enough to keep it in your fingers anyway)... but I know people who are so settled in that I don't think another human being could operate their computers without extended instructions because they've built something that is so much an extension of themselves. ...but I do really like my split keyboards (lately an UltraErgo Wireless and trackball (usually an Logitech M570) for not constantly re-contorting my wrists. Likewise, I have a VESA-arm mounted to the hutch of my desk to get a monitor positioned exactly where I want it without giving up any desk space.