While Cale recovers from his time at NMRA this year, I thought I'd highlight a blast from the past - Monorail! But not LEGO's Monorail, oh no, this sucker's brick built.
I had been following Brickshelf user "hidaka" for some time while he progressed with his brick built monorail. I'm not sure if he has continued to tweak the design, but from what I can tell it looks to be reasonably finished.
What separates hidaka's version from, say, LEGO's version, is that his is a true monorail - the car rests upon and around the single rail. The design is as simple as it is ingenious. Each car has two internal wheels that rest upon the top of the rail. One of these wheels is powered by a 9v system motor which provides motive power. The cars stay on the rails by means of technic bushings attached to Technic axles that hug the rails. Each car only has two pairs of these axles, allowing them to navigate curves.
The track itself is nothing more than a string of 2 stud wide bricks, plates and tiles. To make curves, 1x4 brick hinges are used, as well as old plastic curved rails to help the curves keep their shape. He's even developed a working switch and sloping rails. I've been itching to try my hand at creating a copy of this, it seems as if it would work rather well.