Head on down to the Grim Fandango Network section of LucasForums and you will come across the work in progess of a Grim Fandango-inspired novel being written in several parts.
Highly enjoyable literature or pure piffal in a glass? Why don't you read it for yourself and post your comments accordingly.
Update: There is actually another Grim Fandango novel, written by MeddlingMonk, floating around LucasForums as well. Give it a read while you're at it. It's long. - Jake
Source: GF Novel Thread