Boy am I glad this post turned up. I myself have a small brake squeal at any speed when driving. What I have noticed is these items which may be causing the problem...
A Lip on the rotor that is quite high off the surface of the rotor around the edge. I would think this means the discs need to be replaced, and at the great prices on partsshop, even if its not the problem, it gives me more peace of mind.
Other than that, new pads and I think I will have my problem solved.
I suspect a warped or overly worn disc.
I myself will be repacing the discs and pads before I bother with looking into the calipers which are not something I want to have to rpelace just yet.
If I gotta replace the caliper, I might as well do both at the same time just to be safe hehe.
of course I'm sure I could save lots of cash by doing just one caliper, I figure replacing them in pairs is just for better peace of mind. to me brakes are the most important feature on a car.