Most of the things in The Adventures of Fred are fiction, but some have actual websites!
In Chapter 3 of The Adventures of Fred, "Robbers at Ericc's," Fred is at a restaurant called Ericc's. This is real restaurant in San Francisco. You can visit their website at ericc's-restaurant.com.
In Chapter 8 of The Adventures of Fred, "The Blood-Rushers," Fred is trapped on a plane. He sits in a nearby booth and reads the information magazine in the compartment in front of him. At the bottom of the third page, it says to visit www.rushblooders.com. This website has all the things about the plane, including the snack menu and the informational magazine, "The Daily Rush!"
In Chapter 9 of The Adventures of Fred, "The Skull-Drillers," Fred is in a construction field. The name of the construction company working there is called the Skull-Drillers. They have a website at www.skulldrillers.com.
In Chapters 12 and 13 of The Adventures of Fred, Fred Howard arrives at a restaurant called Tandeeri Sameeza Masalta, which is where he meets Fred Skills. Fred Skills mentions to the manager about making a website for the restaurant to attract more customers. They took Fred Skills' advice and made www.tandeerisameezamasalta.com.