Eggbeater under the hood?

["Colin Barfoot" <Colin_Barfoot@msn.com>]

A new mysterious sound came form under the hood of the Quattro this evening as 
the wife and older kids were heading to VBS.  I popped the hood and couldn't 
immediately see anything wrong. but when the engine was on it sounded like an 
eggbeater i.e. the sound of a hand cranked eggbeater as its blades hit the 
sides of a plastic mixing bowl.  I couldn't see any obvious interference or 
sign of rubbing.  The sound seemed to be coming from the vicinity of the 
alternator.  As the car accelerating away the frequency obviously picked up 
with the engine speed.

So is my alternator about to give up the ghost?  I haven't seen any check 
engine lights or any other obvious signs of reduced charging. 

I was hoping to spend at least one week away from the garage...

Please respoond with your diagnosis so I can arrange for "whatever" to be 
fixed Thursday  (when my carpool drives).

TIA
Colin
86 5000 CD Quattro 308K KM
(if only I could afford that S4 in TO)