I looked around the interwebs, and came up with some great ideas for the Seder:
#2 Miriam’s Tambourine Just leave out the bottle caps if you want it to not be muktzah
#3 Bookmark: perfect for keeping your place in the haggadah
#4 Award–Medal : Why not give one of these to your kids for saying the Mah Nishtanah?
#6 Egyptian Pyramids for the table
#9 Blopens Book cover: Cover your Hagaddah in style
#10 Decoupage plate: make your own seder plate, and make a family heirloom