When you can't choose between Windows and Mac, you don't necessarily have to. Lifehacker reader and Flickr user abe5x didn't as you can see in this workspace featuring multiple machines hooked up to several monitors. Everything is nearly organised and fits into a small space.
One thing we see that could be a little more efficient is the use of two keyboards to control the primary Mac and Windows computers. Why not control them both with one? It seems like this might be a little more comfortable and would take up less space. Nonetheless, this home office manages to fit quite a lot into a small area.
Mac/PC Workstation [Flickr]