If you want to design with them, then color on sandpaper - fairly thick on the rough side.  Then turn the sandpaper over on top of fabric like a plain T-shirt.  Iron the back of the sandpaper (the smooth side), and the colors will transfer to the fabric.  You have to experiment some to get the heat right.  The thickness of the sandpaper and how thickly you colored on it affect what temp you need to have on the iron.

The melted crayon art works great by running the crayons through a hot glue gun - use the crayon in place of a glue stick to melt it.  It doesn't even ruin the glue gun - although I had to run an entire glue stick through it to clean the crayon colors out of it.

If you know any Cub Scouts, they can be decorated to make neckerchief slides.  A lot of Scout leaders are looking for donations of things to make neckerchief slides out of.  Some packs trade small gifts with outher dens or packs at jamborees & campouts.  Our den & pack made slides out of the tape rolls, out of plastic beads & plastic lacing, out of walnut shells, out of suede lacing, etc.

They can be decorated to make napkin rings.

Also, they can be decorated to make Christmas ornaments - small wreaths - by glueing beads and small found objects to them.

You can use them to organize scarves in a drawer.

You can glue several together horizontally and vertically (at least 4 high) to make a pencil organizer for your desk.  You need to stagger them in a V or W shape - not in a straight line - to make the holder more stable.

Hope some of these struck a note!

Decorate the sides and top.  Poke holes in the top and atttach a bead or button to make it easier to open.  Nifty ring box or small jewelry box.

I decorated boxes just like these with school colors & emblems and gave them to my sons when they graduated.  One son uses his to store his class ring, Senior key, etc. - mementos of school days.  I think the other son is using his for spare keys.

String a ribbon through holes poked into one of the points so it can be hung and decorate with wrapping paper, markers, fabric, or paint.  They would make great Christmas ornaments.

The oblong, square or round ones make great doll luggage.  Again with ribbon tied through holes poked in the boxes.  Glue ribbon to the inside of both pieces to make a top that opens more like luggage.

Great for storing scrapbooking embellishments, buttons, & other small items for any crafts you might enjoy.

I saw a cool idea on a recycling board for using a laptop with the innards removed to make a play computer for a child.  Glue a small chalkboard where the screen was.  If you remove the part where the keys are, then you could make a fabric liner with pockets for chalk, colored pencils & paper, etc.  If you are using the chalkboard idea though, stay away from crayons - they can ruin a chalkboard.

2 ideas with no sewing necessary.

Make bolster pillows.  Decorate each leg while flat - using fabric markers or Sharpies.  Then gather one end about 3"-4" from the end and fasten it with an elastic hair fastener (ponytail holder).  stuff it with polyester fiberfill, clean pantyhose (with runs), or a bolster pillow form.  Then use another elastic hair fastener to close the open end.  Voila!  A denim pillow!  Great for picnics, floor pillow in the family room, using in the car, a teen's room, etc.

If a pillow is too easy or boring, cut the denim into 1-1/2" squares and use fabric glue to adhere them in a checkerboard pattern to a rectangle cut from an old T-shirt.  Cut some circles from the leftover denim, and glue 2 kinds of fabric to the backs.  Play checkers!  Store checkers in an old prescription bottle or make a bag from a sleeve of the T you cut up for the checkerboard.  Roll the "board" and tie with a cord made by cutting a couple of T-shirt pieces.  (Pull on them and they will roll into cords.)  You can use the design from the front of the T-shirt for the reverse of the checkerboard, too.

The coated maps would make great placemats/table coverings.

You could cover part of a wall with a large map and faux frame it with paint or even a real wooden frame could be hung around it.  If you have enough maps you could paper a whole wall with them.

If you have kids, you can mod podge the maps onto cardboard & cut them with a jigsaw to make puzzles.

You can make dust jackets for books from paper, non-coated maps.  Great to cover an atlas, world history book, or travel journal.

Get really crafty and trace your route from home to France on the maps in a bright color and frame them individually in your kitchen.

Got an old dresser/cabinet with a finish you don't like?  Cover it with the non-coated maps - overlap them, turn some upside down - and then polyurethane over them for a finish.

Use the coated ones to make a book for a child.  Kids love maps, and the coated ones can be written on with a wax pencil or write on/wipe off pen.  Use them to reinforce math skills and geography with your child.

Those are all the ideas I can think of right now.  Have fun with them!