The main creation is the orange bike. As styling and technique goes it's inspired by Kaneda's bike from the movie "Akira", however, it has some definite differences and improvements. I've included a version that's styled to look like Kaneda's bike, but not a 100% replica.
An animated GIF showing the steering. The wheel can steer about 22 degrees to the left and 22 to the right. While not that much, it's a definite improvement over Kaneda's bike, where the front wheel steered in an almost horizontal axis. (resulting in a truly massive turning circle, if doing anything at all.)
There are plenty more pictures of this bike in the brickshelf folder, and since I don't think I'll be able to give commentary on each and every single one of them you're just going to have to look at them there.
The Akira bike is outfitted with those nifty glow-in-the-dark disks, which happen to look exactly like the dsks on Kaneda's bike. The rear lights and the background are photoshopped, but the disks aren't.
The frame without all the decorations. The steering is actuated with the joystick in the middle, which steers the front wheel. The two 8-tooth gears are there to make sure that when you steer to the right, you actually go to the right.
Anyone who's ever photographed black Lego creations knows how hard it is to get right. I used lots of indirect lighting, and practically surrounded the bike with white paper. (The black parts reflect the paper and, with a bit of luck, show up right.)
It was quite hard to come up with a way to make the steering work with the suspension, but this works like a charm. it uses a flex axle which slides through the hole of the #1 angle connector as the front suspension is bumped.
The bike after a mismanagement with a brick wall. The part near the rear wheel is used in the suspension, you can see it here: http://peeron.com/inv/parts/x928cx1
There's two of them here. What the part does is simple: an axle goes through and the part allows it to rotate 90 degrees clockwise or counterclockwise, and there's a spring inside that turns the axle back to it's original position. The spring is quite powerful.
You can also build the bike if you don't have this part, but then you'll need to build your own suspension or go without it.