We covered a thin piece of plywood (luan) in maps, then sealed it in shellac. The plywood was then attached to the wall to create a whimsical backsplash.
Make a template of the backsplash area with a large piece of paper (we used paper bags taped together). Make an exact cut around edges and double-check the measurements.
Use the template to outline your cutting area on the luan panel.
Place the panel onto the backsplash area. Find the wall studs and use drywall screws to attach the luan panel along its edges and into a couple of the studs.
If you want, place a small piece of wood trim around the edges and nail into place.
When it comes time to remove the backsplash, just take the screws out and fill the holes with joint compound.