Workplace Ergonomics
As any working position, standing up has its own problems if you overdo it. It's also not easy at first to stand up for even an hour. I now find it pretty relaxing to work standing up though. I feel more active even though programming is the least physically demanding thing you could do. And you know how you can easiily spend half an hour following Wikipedia links or reading reddit or digg? That just never happens when I'm in front of the desk standing up. I seem to get into a more committed mode of working in this position.
Like me, he’s using a MacBook Pro, the original iCurve, a Dell display (cheaper, more USB ports, card reader), and the aluminum Apple keyboard (which these days I'm liking more than the iceKey).