If you ride carbon rims (and maybe even if you don't), you should immediately get yourself some Swiss Stop King brake pads! These things just rock. I'm running them on my Zero Gravity brakes stopping Reynolds Stratus DV wheels/rims. The improvement is just amazing (and that is coming off the pads that Reynolds recommended/supplied). I feel that my brakes work equally as well as any aluminum rim combo now.
The pads come in Campy/Zero Gravity, or Shimano/SRAM compatible versions, and come in pairs (total of 4 pads). Unfortunately the Campy version costs $15 more, which I can't understand why, but maybe it's just the "Campy tax").
2007 Swiss Stop Race 2000 Yellow King Carbon Brake Pads for Campagnolo
2007 Swiss Stop Flash Yellow King Carbon Brake Pads for Shimano/SRAM