A tripod doesn't always have to be a tripod - virtually any inanimate object will help, so you can use any ledge or table or column as a stabilizing base for your camera.

Another interesting do-it-yourself piece of gear is what's known as a "string tripod", which is made tieing a steel washer to a string and string to a bolt size of the camera. The string should be your hieght, you can keep the washer under your foot and stretch camera up to fasten it up.

If you want to try making one, all you need is a bolt, some string, and maybe a washer or something for you to step on. The size of the tripod mount is a 1/4", 20 thread size.