whiring noise

["Gene Holtzclaw" <motrv8d@hotmail.com>]

Yesterday while driving, I noticed a noise I've not experienced before. It 
is a intermittant whiring noise. Sort of how a bearing in a fan sounds right 
before it seizes. Would this be a input shaft bearing on the transmission? 
It does it with the clutch depressed or released, does not remind me at all 
of the dreaded throw out bearing failure. Seems a little more frequent with 
engine speed.