Binder Art :
Create a My Art Binder for each child. Place your Children's artwork in
it Be sure to label and date the artwork. You can either 3 hole punch
each piece of art or place in clear protective sleeves.

Purchase an assortment of frame at your local discount store or thrift
store. You can paint them to match your decor. Hang the assorted frames
as if they have pieces of famous art in them only place your child's
art inside of them to display.
picture from www.bungalowinsanity.com
Monthly Art: Choose 12 art pieces and have them made into a yearly calender these make great gifts as well.
Art Collage: Create a collage of your child's entire year of art work. Jane Leni offers this archival piece of art Click here for more details http://www.janeleni.com/?curSection=work