[thstone]

Could be one of the bushings, a shock, spring, ball joint, etc. You're going to have to go through all of the suspension components, one by one, to isolate and identify the cause of the squeak.

When I had a similar issue, I put the car on four jackstands and then took the wheel off and used a jack to lower/raise the suspension assy to try and isolate the problem to a particular component.

Maybe someone else can suggest other (better) ways to perform this kind of check.