No, not that Knight Rider...
Just a few notes on riding at night.
One thing I find beneficial is the use of multiple blinkers. Specifically, I have two PlanetBike Super Flashes: one on the seat post, the other low on the left seat stay. The multiple blinkers really help you to stand out. More than once I've been riding on a dark road, I hear a car coming up behind me but they're around a bend or on the other side of a rise. As their headlight beams paint me, I actually hear the car slow down a bit and I know they've seen me.
I usually have clip-on aero bars installed so I don't really have any room for lights on the handlebars. A few years ago someone on craigslist was posting home-made light mounts that took the place of the quick-release nut on your front wheel. This mounts the light down low. Advantage: really lights up the road, doesn't blind on-coming riders and drivers (if properly aimed). Disadvantage: might not catch drivers attention. Currently, when I have a light on that mount it's my Planet Bike 1W Blaze. I usually leave it in blink mode to provide better safety, rather than allowing me to navigate.
Helmet mount: excellent idea. I really like my Niterider Minewt 250 mounted on the helmet. Coming up to an intersection, I briefly point it at any other cars in order to announce my existence. Advantage: turn your head to point and aim. Disadvantage: weight or dealing with power cable. I actually tried to put the Niterider on the axle mount mentioned above, but the design of the clamp doesn't allow it to tighten to the point where it won't fall off. If it was on the handlebars, it wouldn't matter because I could just tip it back up. But due to the open end of the axle mount, it could fall off.
Regardless of where your light is mounted, it needs to be aimed properly. Yes, aiming your lights isn't just for your car headlights. For rear-facing lights you want to point it so that it's visible to a driver coming up behind you, slightly towards the left. You also want to have your rear lights affixed to a static mount point, the only exception being a blinky on the back of your helmet. Those fabric loops on a saddle bag or backpack should be avoided, they are usually too large and the light is not securely affixed in position so it wiggles around and may point off to the side or down to the ground.
You also need to consider passive visibility: reflective materials and stickers. The best reflective tape I've found is Reflexit V92 in silver (available from http://www.identi-tape.com/hi-intensity.htm). Put small snippets of the tape on the chainstays, seatstays, head tube, and anywhere else you think will provide good side visibility. Don't forget your helmet. If your wheels have room for it, you will also get a great deal of benefit by placing reflective tape on your rims.
High-visibility traffic vest: even though I have one, it's just a little too fredly for my tastes and I rarely wear it. But it does provide excellent visibility. The specific one I have is just a cheapo traffic safety vest from Home Depot. It will fit over any amount of cycling jacket and sweater, and the reflective stripes are nice and wide. The only problem with it is that it only has one velcro patch for closing, but I guess I could use a safety pin to keep it a little more secure (not that I've ever had a problem with it popping open). I also am skeptical of the benefit due to the angle of my torso while riding. If I rode a hybrid or had an upright position, I think the vest would provide better visibility. But I'm usually hunched over on a road bike and may even have a day or lumbar pack on.
Oh, and listening to your iPod or MP3 player while riding? Day or night, that is stupid.