[@Doltboy]
I use http://sig.grumpybumpers.com/ for mine but I know there are a lot of sights that can provide one. They're pretty easy to make, though they work best if all the images are the same size.

So I can't be sure which title or quote you're referring to but I agree, a great balance. I always got the feeling that Aziriphale and Crowley were based on the authors themselves, with Gaimen being the cool, slick bad boy and Pratchett the more reserved, studious one.