To have a comfortable standing position, you really need to be able to move your monitor separately from the keyboard. Most monitors doesn't really allow you to adjust their height, even iMacs just allow you to tilt the screen, which isn't what you want. If you want to switch position during the day, you either need a really good desk where you can rise the monitor separately or a monitor where the "neck" extends.
If you don't want to use the keyboard, you can set it aside, of course. But it's there for you to use it if you like.
Most companies don't really think about it, providing adjustable desks, external monitors, dockingstations, etc. is just the norm.
You do it momentarily to look at what your manipulating, but its not very comfortable for extended periods, since it requires that you're either craning your neck to look at your lap or keeping your arms extended out in front of your body.