I was watching "Fringe" at hulu.com when towards the end of the show this image of "Olivia's" computer was shown.
I cannot be certain but it sure looks like Ubuntu to me. Though laid out very simply, no real clutter to speak of. No top Gnome Panel present and I couldn't be sure because of the focus, but the Ubuntu logo may be in the left side of the panel.
You be the judge, I know this much. that isn't Windows and they prominently display the Dell Logo throughout the show. My guess obviously leans towards it being the Gnome desktop, modified obviously, but still Gnome and the color scheme smacks of "Human"