Currently, I'm using a full sized Microsoft "natural" keyboard. The kind with the angled split. Along with a separate mouse. I really hate this keyboard, by the way.
I keep them in my cabinet. When I need to do admin stuff, I flip up the top on my control panel, lift out the keyboard and mouse, close the control panel, and sit them on top.
I really don't use the keyboard that much except when I'm configuring my cab. I don't play PC games on it or anything as I have a 15KHz arcade monitor.