Clutch squeak?

This morning I got into my car and I was picking out a CD to listen to...I had the door open, engine off, and I put my foot down on the clutch, just as a reflex I guess since that's what I do anytime I get in to drive. Anyways, I heard a rather funny sound, like a squeak coming from outside. I pressed the clutch in a couple more times and it did it everytime I'm not too worried about it, it's a mustang I've never power-shifted, car only has 36k, it's an 02, I drive it like a grandma...most of the time at least...I can't hear it squeaking with the engine on, but my exhaust is pretty loud so who knows...

I was just wondering if anyone else has heard this and what it is?

I dunno, I thought throw out bearing was when the car was on? I really can't hear anything with the car on whether the clutch is in or out. It only squeaks when the clutch is being pressed-in at about the half-way point. It kinda does on it's way back out, but it's not very noticeable.