The Mercantile Flea Market has Victorian Fireplace Tiles on sale. At only $1.99 each, these tiles can be reused and repurposed for a variety of things.
These would make a great foundation for a mixed media or altered art piece. You could also adhere your favorite clear stamp onto the back side of the tile so it's ready to go and looks quite special on your desk.
Betsy glued a paper clip onto the back of her tile, clipped a photo to it, and wrote on the tile with a dry-erase marker. The dry-erase marker will easily wipe off with a cloth and you're ready to inscribe another caption for another photo.
What a great gift for a parent's desk at work ...
This is a display you can change over and over again.