Via Joystiq, an article at the GameInformer site generally about Valve's upcoming plans for Half-Life, Team Fortress, and Portal. In that article, they mention that some of the writing for Portal is being handled by veterans from the Old Man Murray site. From the article: "When you have that style of game it could just be very stale and very dry. It's just puzzle solving and you could put in a little techno music in the background and leave it at that. But we thought it would be much more interesting if we introduced this idea of the narrator. The original idea came from the training room in Half-Life 1 where you had that voice that was talking to you and whatnot. She was a little bit cynical, but not nearly as so as the voice in Portal. The writing for that is being done by Chet [Faliszek] and Erik [Wolpaw] who used to be Old Man Murray. They're at Valve now and one of their first projects they've been tasked with is to do the writing for Portal. So if you were a fan of Old Man Murray you're going to be a fan of that voice in Portal because it's the same wry cynicism."