Kony.. YOU, my friend, provide answers and clarity in a sea of confusion.
Thank you so much for sharing your wisdom. You ROCK!

Forget about idle temp. The system needs to be adequately cooled to
remain stable while running for extended period of time at full load.
Popular programs like CPUBurn or Prime95 can be used to attain a load
temp, after 30+ minutes of running. THEN note the temp, and whether it's
stable, particularly in Prime95 after running for at least several hours.
Also check the temp of other components like the hard drive, video card.
They may need the additional case airflow more than actively, well cooled
parts like a CPU. Sometimes a fan isn't even needed, merely increasing
the front bottom air intake vents (and the metal behind them if necessary)
is enough. Take care not to divert too much airflow away from the hard
drive bay, usually a decent case is designed to have a large portion of
the air flowing past the drive(s).

With ASUS's Smart Doctor Software I get to detect the GPU temperature, so
that's handy for doing the load test. The monitoring software also has a
field for displaying graphics card RAM temp, but it's blank, so I assume the
feature isn't available for this card. But how does one gauge hard drive
temp. The drive felt like it was getting pretty toasty after just running
close to idle for a while. It's a Barracuda ATA IV - ST380021A. I'm
assuming there is no thermal sensing software for the HD.

It's probably wearing out and needs lubed. Such a thin fan with a tiny
bearing needs a relatively thick oil, better a very thin grease, else
it'll just run out and need lubed again sooner. If it's overly worn from
extended periods of running "dry" the bearing may be too far gone to last
much longer regardless of lubing it... generally the best way to handle
those crap video card fans is to lube them before they ever start making
the excess noise, else replace the whole heatsink/fan assembly instead.

I took a peak on USENET looking for more info on how (and with what product)
to lube these fans. Do you agree with the 3rd post at this thread
http://tinyurl.com/2dwek? regarding the technique and product
"non-conductive silicon based lubricant"?

Thanks for the other suggestions. I'd like to try giving it a shot of lube
first. I don't think it's too far gone. Hopefully a little lube will do
the trick.