It's not really the pedal that squeaks, it's the shoe rubbing against the pedal. The pedals are Wellgo SPD clones, platform on one side, clips on the other (similar to the Performance campus pedal).
The only thing that I've found that works is to spray the pedal with lubricant (like WD-40), but it makes a mess of the pedals and makes my shoes greasy.
Any other ideas? This is my second pair of shoes, and the first pair squeaked also.