Today I hacked together a standing desk at the office. My main work machine is a MacBook Air that I plug into an external monitor, mouse, & keyboard, so it was a pretty easy transition.
I found some old shipping boxes in the office and stacked them up until I found a comfortable height for everything. It looks pretty bad, but it works fine. You can see a picture here. I think I actually would prefer having the keyboard another 2-3 inches higher, for my wrists.
So far I am loving it. I feel like my brain is more active. The bottoms of my feet hurt, but in a good way. I might try and do this at home, too.