I blatantly and shamelessly stole that title from BLUE.
Back in April of 1997, many comic artists participated in a massive swap, in that each of them did the art for a different one. Some were done by friends for each other pairing off, others were done in large "circles".
He's got many of them scanned, and you can see things like the swap between Blondie and Garfield, Dilbert and Family Circus, and chains like On The Fastrack as drawn by Sherman's Lagoon, Sherman's Lagoon as drawn by Baby Blues, Baby Blues as drawn by Herb And Jamaal, Herb And Jamaal as drawn by Broom Hilda, and so on.
Good Cool stuff.