I've heard that sound when starting...I read a something about it on another thread...and I remember someone saying that it was due to the cold weather, other people had there own ideas.
I noticed it when I first got my element...I have remote starter, so I usually aint by my car when it starts so I havent listened for it lately.
My '09 SC does it in the morning when the motor is cold. Moisture on a bearing? I started it this morning and heard the screach. Shut it off after five seconds, and started it again, with the screach. I warmed up the motor for a few minutes and shut it down, started again, no screach. I'll try to pinpoint it the next cold startup.