Recently, I've been experimenting with working standing up, by placing a portable file box on top of the folding table I use for a desk and putting my laptop on top of that. So far, I like, as I can move around much more, switch from foot to foot, stand on one foot, and stretch out my hip flexors which get far too tight sitting. In fact, I can even put one foot behind me on my chair, and lean forward towards my desk for a really nice stretch.
My cats however, are not at all happy with this new development, as they view my working time as optimal lap-sitting time, which they obviously cannot do while I'm standing (although when I was doing the stretch mentioned above, one did sit on the leg that was on the chair.) While I feel a little sorry for them, I'm also pretty sure that being locked into position by a fifteen pound cat is also not good for my stiffness, so this is overall probably a good development. And they have plenty of other places to sit.