Yikes

So recently I've noticed a sound coming from my front left wheel when I drive. It sounds like rusted metal rubbing. At first I suspected the wheel bearing but the noise amplifies when I step on the brakes.

When it first started a month ago, it was a very quiet "tsk-tsk-tsk" sound. It has gotten worse. I know the brakes on 2nd gen TLs have been known to be junk, so I'm starting to suspect that perhaps the caliper is bound up, or the pad is sticking ever so slightly.

The car doesn't seem down on power or MPG. I haven't run the car far enough to feel if that rim gets hot.

Possibly relevant information:

A month ago when I was coming home on spring break I was on I-64 and someone came into my lane. I swerved to avoid and went into one of those tail spins where steering to get out of it only makes it worse.

Thankfully I didn't hit anything but when it happened I mashed the brake pedal and locked the wheel in both directions twice. It was a few days after that that I noticed the sound. Could this have anything to do with it?

Skirmich

Have you tried to remove the wheel and Inspect brake pads and the Caliper? Isn't hard at all..

3.2TLc

Yeah, pull the wheel and check the brake parts as Skirmich suggested.
Might as well take the pads out, then clean & lube contact points to the caliper and pins.
Check the rear backing shield. Sometimes they can get distorted, rust or stuff lodges in them.