Paper

Papercraft is capable of some truly interesting and impressive feats. The paper camera has been around for decades, but the instructions are now readily available thanks to the web. Building one is relatively simple. You download the templates, print them on thick cards stock and assemble the camera. The Dirkon is one of the most common examples and it's so cool if executed properly. You can check out this link at Pinhole.cz for instructions and some sample images. Just be sure to keep it dry and give it lots of light as the F/130 aperture isn't exactly speedy.
Garbage Containers

The Trashcam project was created when some clever German men realized they could make trash bins (the word Dumpster is actually a registered trademark referring to a specific brand of garbage container) into easily portable, very large pinhole cameras. They shared some of their amazing images on a Flickr page and captured the imagination of the internet. The final images have the heavy vignetting and ghostly sharpness for which pinhole photography is known. It's such a good idea because the camera itself is both easily portable and infinitely inconspicuous, which is good when you need extra-long exposures.{C}
Garbage

If a garbage container can be made into a camera, then it should be no surprise that the trash itself can be used to take photos as well. 20th century Czech artist Miroslav Tichy used items at his disposal, like thread spools and paper tubes, to create a camera that looks like it has spent some time at the bottom of the ocean. But, it worked. Appropriately, he allegedly developed some of his images in a bucket for lack of a dark room. It's also said that people sometimes thought he was pretending to take photos because his camera looked so ludicrous. The images he created were extremely distinct and act as a nice reminder that we should appreciate just how awesome and convenient our normal cameras are.