We have been exploring the Robert Sabuda site and spent a while working on "Simple Pop-Ups You Can Make" and while we feel simple may be a bit misleading, it was fun.
This month on the site, they are giving away a copy of Maurice Sendak's Mommy? illustrated by frequent Sabuda collaborator Matthew Reinhart.
I'm not generally a big fan of holiday-themed kids books (mostly because you have to either pack them away or put up with Christmas in July), but this is an excellent choice for both Hallowe'en and year-round. Perhaps not for the youngest of readers as this is one of the more fragile pop-ups, but an excellent choice for bed-time reading by tired parents as it's just one word over and over.