It's not as bad as it sounds.... but I heard this kind of a squeaking noise leaving work today, listened to it and it was kind of acting like a u-joint squeak so I didn't think it was a big deal.
I have like a 20km drive home, with a stop sign halfway in between. Taking off from the stop sign, I noticed it was louder than before so I had a look and couldn't see anything. I didn't have anyone with me so I couldn't hear from the outside while the truck was moving. I get home, park the truck and figure I'd have a look later. Later on in the afternoon I got my fiance to drive the truck while I was beside it and I could tell the noise was coming from the passenger front wheel, so I pulled it inside the garage and took the wheel off, and found that one of the little tin clips that sit on the caliper bracket that holds the pads had bent up and was dragging against the inside of my wheel.
It had snowed a lot here the last 3 days and I was on some backroads plowing through 3 foot high drifts, so I figured maybe a piece of ice or a stone got jammed in there and bent it up?
It scraped a fair bit of material off the rim as you can see on the caliper, but it's not very deep.
You can see in the last pic that it's the clip at the bottom that was bent up.