So the point is to have fun with a group of friends, right? But one player couldn't make it because she has to cover somebody at work or he has to stay home with a sick kid. What if you could call them up for a few minutes and include them just for fun?
How? Well, that part I'm not too sure. I'm imagining some party game type questions. Maybe have a bunch of generic questions on cards and players have to pick ones that they think will elicit the answers they want from this particular npc (Yes/No/#s) when asked of the phone-a-friend.
"Have you ever driven down a street the wrong way . . . while sober? How many cats have you owned in your life?"
I don't know, maybe something else. Whaddya think?