You should also supplement your headlight with a front blinker like the Vistalite Nebula. The smallish headlights on bicycles are not large enough in diameter that drivers just don't notice them like they do with car headlights no matter how bright they are, the flasher will grab their attention fast.

Forgot to mention taillights. The Cateye brand is the best for the money; including the LD600 and 1000. The 1000 is the brightest on the market but one of the more expensive tailights at about $40 while the 600 is plenty bright for about $20. I have the 600 and it's blindly bright, and if mounted vertically it's visible from at least 180 degrees...as is the 1000 as well.

Also those little barend LED plug lights are a great addition to a taillight.

Also use reflective straps around your legs, the up and down motion catches drivers eyes...if they somehow miss the red LED's beaming at them!