Book Pages. A little sturdier than newspaper, this is a wonderful and whimsical look for a small room. Use pages from a favorite picture book in a kid's room, a book of romantic poetry (try French!) in a bedroom. For a similar aesthetic, try cards from card catalogs!
Newspaper: Although this wallpaper in Jason Wu's home in this month's Elle Decor is only inspired by pages from a newspaper, why not use the real thing? To give it extra durability and to keep it from yellowing, paint a layer of polyurethane over it. The polyurethane will also make it easy to wipe down. No wonder it's a popular look in French cafes. Use a foreign newspaper (we're partial to Chinese and Japanese papers) for a touch of exoticism. Takeout menus, used sideways, are another option.
Post Its: I still love this look. Not only is it colorful, it's also textural. Keep an extra pad of notes around to replace those that fall or, more likely, get used up!
Aluminum Foil: A bold look for a hallway or to create a focal point in a living room. Whether you use the dull side or the shiny side, a bone folder helps to smooth it out. A blow dryer helps it mold around curves.
Paper Bags: The familiar brown ones create a leather-like look that's an interesting background for a rustic, industrial or mid century modern look. Tear bags into generous uniform pieces (save any pieces with straight ends to apply along the edges of your wall). Apply to the walls with wallpaper paste, overlapping the edges. Leave as is, wash with a glaze or watered down paint (try a metallic) or coat with sealer. For detailed instructions, see Wuvie | How To Brown Bag Your Walls and More.