Due to my extended work+school hours, for me bike commuting almost always means night riding, even around summer solstice.

I have all of the following mounted on my bike:
Super bright Red blinky light (Cateye TLD-1000) on the end of the rear rack
4 spoke lights mounted on the front wheel, for side visibility (Hokey Spokes)
Super bright White front headlight (Exposure, rechargeable bright LED)
Second white front headlight (Cateye Opticube) that I keep on strobe mode (it is also a reasonable better-than-nothing backup light in case I've forgotten to charge my LED light)

And then I wear:
Plain ol' red blinky light on the back of my helmet
Bright yellow vest or jacket or rainjacket

So far I've been able to see and be seen quite well with this setup. Many cars give me a wide berth, and are generally polite because they don't get scared when I appear "out of nowhere!".