If you want to "cash-in" on all of those after holiday sales, look no further than your Mac's desktop. Apple is starting a new winter promotion for iPhoto books and calendars. By using two promotional codes you can save 20% on books and calendars through February 29, 2008. Apple says that the book code will also work in Aperture.
For calendars, use code: NAWinterCal08
For photo books, use code: NAWinterBook08
Thanks to everyone who sent this in!
Update: a recent commenter shared with us the codes for the UK iPhoto:
For calendars, use code: EUWinterCal08
For photo books, use code: EUWinterBook08