Seriously cool Kai! I'm only missing two of the Discworld novels at this point, so I recognize all of those characters.
Many of Swann's (S.A. Swiniarski, or Steven Krane. He writes under all three...) are set in my hometown of Cleveland, Ohio. I don't really recognize any of the characters, but I know most of the locations.
There's two mystery novels that I've read where I've at least seen the people the characters are based on:
"Bimbos of the Death Sun" by Sharon McCrumb. Don't let the title fool you. It's a joke from within the book. It's a murder mystery set at a science fiction convention. I swear I know some of the people mentioned.
The other is "Knight Fall" by Mary Monica Pulver. That one I have met several of the people the characters are based on.