I had to do a brake job at 29,500 miles. All of my pads front and rear were less than 3mm in braking material. I would guess you need a brake job. The pads have a little metal tab that is designed to scrape along the rotors and make a screeching noise to alert the driver that it's time for a brake job. If you ignore it then the pads will wear down more and eventually just scrape metal to metal and cause more damage.
I would simply try and take a good look, You should be able to see it through the wheels and see how close the tabs are to the rotors. Or you can just jack it up, remove the wheel, and really take a good look. Even pull the brakes off. Check the fronts and rears.
This sounds like it's the problem to me. It could be just one tab at one wheel scraping along as you stop, just slightly enough to sound like a plastic bottle being squeezed and twisted.
Since it only seems to happen while braking then I would just take a look and see what's going on down there.
Last edited by CruisinG6; 03-01-2012 at 05:08 PM.
Reason: Removed all the useless rambling