UPDATE: See some sample pages of the book here.
SECOND UPDATE: More good news! When you order the coloring book, you'll get a link to download the song "March of the Zombies" by Schnauzer Radio Orchestra. The song was written exclusively for the Monster By Mail project by Rob Goebers. To get the MP3 make sure you open the thank you note that is sent after your purchase.
THIRD UPDATE; The coloring book has been Boinged! Thanks to Dan for the heads up. How could you not be happy with this review from Cory Doctorow himself:
"Len Peralta's new coloring book, "Monster By Mail Presents: AARGH! The Incredibly Ghoulish, Frighteningly Creepy Coloring Book Of Death" reminds me of my favorite monster stickers and coloring books from the Seventies -- scary in a Munsters-y kind of way. Judging from the volume of this kind of art at Comic-Con last week, it seems to me like there's some kind of revival underway. I heartily approve. The coloring book is $11.26 from Lulu or $6.25 as a PDF. Perfect rain-of- frogs-day fun for the little monsters in your castle.Wow...just wow.
FOURTH UPDATE: Thanks to Ben, the coloring book has been Dugg. Can you Digg It too?