Mike,
Thanks for the tip, I'll try that.
As of now though, I took it over to the mechanic, we drove it again, and he STILL didn't hear it. So we went back over and I told him to take of the wheel and inspect. Another mechanic, Tony, really nice guy, jacked up the car, and spun the wheel, we could hear the squeeking/grinding noise. Then, he took the wheel off, visually inspected everything, said nothing looks out of whack. Then we spun the rotor without the wheel and couldn't hear anything. It all sounded normal without the wheel on. Then we put the wheel back on, spun it again, and we still couldn't hear the noise. It had gone away again!

Mike, and those directions about grabbing the rotor will help me determine if in fact it is a problem with the wheel bearings?
Thanks!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)