Interesting. I'd like to build my own keyboard, but my crafting skills are not good enough for it. It's a pity how few tenkeyless mechanical keyboards with a ctrl<->capslock dip switch there are, and most of them don't allow you to install matching custom key caps. I'm currently using a Pok3r, which is okay, but I really wish there were more custom keyboard options on the market.
If you boot several OSes, use ssh connections, and remote desktop connections, this really becomes a hassle. It always breaks at the wrong moment with some kind of OS update. Especially key remapping on Linux is a horrible experience in the long run.