I just started hearing a squeaky noise in my right front tire. After sweating it out thinking I had to buy new front bearings after just putting my lift on and spending a crap load as of late.(Lift/35's/track bar)I came to the conclusion that it was my break pads.
Apparently there is a metal bar that hits the rotor to let you now your pads are low while you drive. It compresses as you hit your breaks and stops squeaking.