It's most likely the throwout bearing. Especially if it sounds like this:
http://www.ft86club.com/forums/showthread.php?t=56882
I had mine fixed under warranty, but one of my buddies wasn't as fortunate. He had to pay for it out of pocket, which was the same cost as getting your clutch replaced. Depending on how much mileage you have and how you drive, you might as well get your clutch replaced at the same time since it will already be opened up. Toyota gave him a high price, as expected, so he just got it done at Touge Tuning. Squeak be gone.