I like buying entertaining things for the fridge but I also like to be practical. Instead an Amazon search will quickly reveal that you can get 50 Rare Earth Magnets for $2.99. I use those for my "art" gallery. They are unobtrusive and allow me to quickly change the display.
This month my freezer is covered with the personal photo cards we received this Christmas. I am learning to not be a saver (goes against the genes) but I do enjoy these photos and thought, "Why not display them for a few weeks?" I don't have to keep them forever but I can enjoy them for awhile. And they did start fun conversations with friends and family that came for a cross-country ski day this past weekend. It is important when designing living space to keep it personal. A collection on the fridge door is one of those touches that communicates "home" to me.