Okay, so I was on my way to work this morning when I heard something strange... It sounds like a "pop" when I apply the brakes, and another "pop" when I let go of the brakes.

It DOESN'T happen when I apply the brakes slowly, and it doesn't happen all the time. I didn't feel anything different in the pedal, and the braking doesn't seem to be affected by this. I don't hear squeaking or grinding or anything else like that. When I got home from work I checked my brake fluid, and it hadn't changed. Does this sound like a caliper sticking?

probably has to do with the brake booster/master cylinder assembly.

you wouldn't hear an audiable "pop" from the caliper

Ideas then?

^replace your brakebooster and master clyinder?

Just to update you fine people, I found that my rear driver side caliper was missing one of the bolts that holds it to the backing plate, so it was just wiggling around on the rear disc... so I went to the hardware store and got a new one and fixed it. No more popping. No warped rotor. Repair done and cost me $1.52.

Woot.