Gotta say though, don't make fun of the guy for making bongs out of cheap materials. Big expensive bongs are cool, but I never go far from home with mine. Its too valuable to me and I've had some great bongs/pipes confiscated by the cops (Cennar's Jesus pipe would be a good example).

So if I have a lot of walking to do, usually a third lung made from an empty 2 litre pop bottle, duct tape and a plastic bag works nicely. Not as pretty, but it gets the job done.