Good info. Didn't know that. As for the fuel mileage, I still get pretty good mileage for the way I drive, at least on the highway.

And as for the E-brake, I do use it when I park, but if a shoe was stuck, wouldn't I notice the horrible pull from it?

I did check (not thoroughly) the rear rotors last night for excessive heat after a short drive. Needless to say, the left rear wasn't hot at all (the one I suspect to be the culprit, since the noise is coming from the left rear of the car), the right rear was a little warm, but nothing to make me think it was overheating.

After the info you guys gave me, I don't know whether it really is a caliper or it's my E-brake. I'm still thinking is should be the caliper, but I've only encountered this once before on a different car that I didn't use the parking brake on, and it was the front brakes.