it goes away after maybe 20 seconds or so. I've had numerous people tell me its everything from the tensioner to the power steering pump to the belt tightness.
Every time I go to start the car (cold) it makes this horrible squeaking sound on 1996 Geo Prizm
Could be a belt slipping but sometimes the best thing to do is take it to a professional and let them keep it long enough so they hear it. On manual transmission I have heard simulary discribed noise from the clutch.
it could be any of the things mentioned but start it again when it is cold and open your hood and listen from where the sound is coming to pinpoint the source and then fix it