In the book Cell, there is a character named Alice, much like the Alice in the town of Tull from "The Gunslinger". Later on in Cell, a couple guys in an SUV drive by and toss a cinder block which strikes Alice in the face, nearly caving her face in. Now as you might recall from The Gunslinger, Alice had a huge scar across her face. Cell was the first book by Stephen King that I read, and The Gunslinger was my 2nd, so i immediately made that connection.

The reference to Charlie the Choo-Choo (the ride) is apparent as the Raggedy Man's clothes hang at the end of Cell. Charlie the Choo-Choo is also the name of the book that Jake receives in book III (The Wastelands) of the Dark Tower series describing a soon to meet, Blaine (the pain).