I can tell you from working in the cabinet business, there is certainly no shortage of used cabinet doors in all shapes and sizes.
While some may look a bit dated in the kitchen, those same doors can look just great in another context.
Repurposing doors, mouldings and other building materials saves money, and keeps them out of landfills.
Bed Headboards
The DIY duo over at Remodel This House have a photo tutorial showing how quick & easy it is to build a beautiful panelled headboard from a few doors rescued from a Habitat ReStore.
Add a couple of posts, a frame, top it of with some mouldings and a paint job, and you’re there.
Wall Art
Caloway Creations has a nice example of how a decorative paint job can turn an otherwise plain door into an art piece.
Apartment Therapy has examples of doors that were turned into picture frames by applying artwork to the panel with spray adhesive.
Chalkboard
This is an easy way to turn a cabinet door into a message board to hang by the phone from My Repurposed Life.
You can get chalkboard paint at many home centres or art stores. In this case, the chalk holder is a tile rack from an old Scrabble(tm) game.
Here are a couple of ideas I’ll add to the list:
Freestanding Room divider
Use three or four 60"high pantry or broom closet doors to make a freestanding room divider. Attach 1 1/2" x 1 1/2" posts about 68" high to the edges of each door to raise the panels about 8” above the floor.
Add decorative hinges between the posts so the panels can be angled in a zig-zag. Fill the holes and give it a funky or distressed paint job.
Wall panelling
This might take a bit of searching to find enough of the same style and right size doors to suit, but it could be be practical for small room like a bathroom or an entry.
Most wall panelling (sometimes called wainscoting) is around 36- 39"high including the chair rail which caps it.
Several equal width 30" to 32" high raised or flat panel doors would work with a 5" high baseboard and a 1 1/2 or 2" chair rail to finish it off.
Keep in mind to do this you’d also have to add a 3/4" backer to the baseboard to bring it out from the wall to match the panel thickness.