Use scrapbook paper of sky and grass and modge podge to a magnetic board. Then cut out the photos of your choice, laminate, and attach a magnet.
We found this tutorial at Puppy Love Preschool, and the original purpose of this board was to display animal habitats in a museum, but really - the sky's the limit here. We like their suggestion of changing out the magnets for different seasons. You could display flowers and baby animals in the spring, a family driving to the beach in the summer, etc.
(Image: Puppy Love Preschool).