I like that idea of keeping the ideas as a means of remebering Nik, there was a similar idea used in a movie, I think it was regin of fire (dragons taking over the world movie) where the americans were keeping the dogtags of the guys who died as a means of remebering them. it would be nice if this was what thery were doing, but it could have to do with something that was going down prior to the zombies, and they are hanging on to them just in case thing go back to "normal" and they can get "upgrades" to what life was before, sorry bit of a ramble, not even sure it that last idea made sense.