Serene night biking
I have achieved my final form for nighttime biking. In short, it is to emulate a firetruck.
Road biking
Bicycling on roads is dangerous. Cars are a lot bigger than bikes, have a lot less to lose from any sort of interation, and it shows. A lot of drivers are distracted, many are completely absent from the task at hand, and a small number are actively hostile to having anything else on the roads that are built exclusively for them. That’s just during the daytime.
Night biking can be quite a lot more risky, but the tables are turned. If you bike at night without lights or with inadequate lights, then you have no one else to blame. There is a reason cars are required to have numerous lights and reflectors at night. The speeds at which vehicles (both bikes and cars) move on the road only work safely at night when they are well lit.
Basic lights
You need 4 lights on your bike: a pair front & rear, all of which are bright (i.e. made in the past 2-3 years). If your lights were made before 2010, they’re likely just not bright enough to compete with all of the other light sources in even a semi-urban area. The Sweethome has a great simple recommendation, a Cygolite pair consisting of a 350 lumen headlight and a 2 watt tail. While this setup is perfectly adequate for relatively safe night biking to get to the level of serenity you need a second light on each end.
Up front, get one of the brighter Cygolite models (500 or 550 lumens) and for the rear a NiteRider Solas 2W. The idea here is to have a steady-burn light (the Cygoligte 500 up front and the Cygolite Hotshot in rear) to make you visually easy to track and a flashing light (the Cygolite 350 and NiteRider Solas) to attract attention whether cars are coming from front or behind.
Helmet lights
In addition to two pairs of lights on the bike, I also have a pair on my helmet. I use a CatEye Omni 5 on the back, though a CatEye Rapid 5 or other moderately bright, lightweight light would be good in this role. For the front, I have a NiteRider MiNewt USB but any lightweight, 350 lumen or greater helmet-mountable light will work. Having a light on your head is phenomenally useful for getting notice from inattentive drivers, particularly those at cross streets looking to turn.
edit: M'verygoodfriend Marshall pointed out that NiteRider Lumina Flare fills both of the helmet light roles very well.
Daytime use
Having bright-ass lights also makes biking during the day a more pleasurable experiene. Just run all of your brightest lights on flash mode (in this case, just one on each end of the bike) to get drivers attention. Since adopting this practice, particularly with the very bright NiteRider Solas rear, I now have cars that will dutifully slow down behind me and wait for a safe place to overtake.
RevoLights
RevoLights aren’t that bright—I’d guess they put out less than 100 lumens each—but they’re apparent size make them novel and eye catching. They’re expensive at $200 a set but if you ride a lot at night in urban areas, or just want to look very flash, then they’re a good addition to your night biking setup.
More info
If you want to know more or explore all of the bike light options, check out Nathan Hinkle’s Bike Light Database. These reviews started with the detailed headlight and taillight reviews from the Bicycles StackExchange blog which give a lot of information on his methodology and the vast array of options in the bike light world.