[MATCHBX]

Or a froze caliper.

I had a problem with my rear brakes one time like this. It turned out my brake pad had cracked in half diagonally. When I would back out of my driveway, the pieces of the pad would slide against each other and basically was applying itself to the rotor and would bring the car to a halt before I was halfway down the driveway. It probably isn't that but it sounds like you may have a caliper that is sticking or your pads are worn out. When was the last time you replaced them and how much fluid is in the master cylinder right now? If the fluid level is down, it is the first sign that either you have a leak or your pads are worn out.