Josh Susser's blog
At Pivotal Labs, we spend most of the day pair programming. The typical setup is an Apple iMac with a keyboard and mouse for each developer. We've been using the 24" iMacs for a while, usually with a second 17" display off to the side. But all our new machines are 27" iMacs, and those are so big we don't usually use the second display. The pair sits side-by-side at a desk facing the screen together. Here's what it looks like:
We have had great success pairing this way at Pivotal. But while it is a good setup in a lot of ways, it falls short ergonomically. First off, both people have to sit off to the side of the display, which can cause leaning, slouching, and twisting to get into a position to both see and type. And it's also hard to actually look at your partner without craning your neck around. Even though the desk is wide, keyboards and mice take up room, so there can be a lot of jostling and adjustment on the desktop, and chairs and such can collide as well. Those things aren't terrible, but they do detract from the experience and my spinal fitness.