Then I did the same thing with pictures that my 18 month old would recognize. Like this...
Then I cut them up, told the kids to go hide in their rooms and then I taped them all around the house with my painter's tape (but what actually happened when I told them to go hide was that my 18 month old chased the 4 year old into his room screaming and they slammed the door shut with excitment). I think I'm gonna right a book about 101 things to do with painter's tape. I never knew it was such a versitle tool, er uh, object - or whatever.
After my 4 year old asked about 412 times if it was time to come out yet (mind you it was a time span of 2 minutes) they both came charging down the hallway with the anticipation that Santa had just come.
The picture below shows that I taped all the babies' pictures in one place and just said "Bring Mommy Elmo" and he would. I taped the 4 year olds numbers out of order all through out the living room and he had to bring them to me in order. After he did, I would tape them all up again and tell him to bring numbers out of sequence. It was a little more tough for him, but he loved it.
As always, post any variations that you have. Enjoy!