Every now and then you'll see a photographer walking around with a monopod for their camera, instead of or in addition to their tripod. There are even some tripods that turn into monopods, or where you can remove the central pole to use as a monopod. You can even find collapsible monopods that are light and easy to carry around. There are inexpensive monopods and some more pricey monopods around.
Monopods don't give you as stable a platform as tripods do, but they do come in handy when your regular tripod is too heavy or bulky to carry around, or you're just out walking around and don't want or need to have a super solid platform. They're easy to carry around and quick to set up. Monopods can also be used to get some pretty neat shots from high up because you can hold it up in the air and give the camera some extra elevation for your shot.
All you need is a wooden broomstick (around $7 from Lowe's if you don't already have an old broom you can cannibalize), a 1/4"x20 bolt, a couple of nuts for the bolt and a drill. The project calls for a hanger bolt, which I couldn't find so I just used a 3" bolt. I used a 7/32" bit to drill a hole in one end of the broomstick for the bolt, put the two nuts on the bolt and tightened them against each other and then screwed the bolt into the hole. Make sure to leave enough room so that you can mount your camera.
The bolt is a little off center because the drill bit walked a little when I started drilling. It doesn't affect the use of the monopod though.
The project also suggests a spike for the other end so that you can stick it into the ground but I figured with the way I am, the probability of accidentally impaling myself (or someone else) was too high. Instead I got one of those rubber chair leg caps to fit on the end. This also lets my camera monopod double as a walking stick.
Total cost was less than $9 including sales tax.