I have a 92 coupe with a little over 16K miles on it.  Recently I have noticed that when I am idling the car in neutral with the clutch pedal release I get this thinny clattering noise.  As soon as I depress the clutch pedal the noise is gone.  Other than the noise there is no operational issues with the clutch.  Is this something I should be worried about?

I doubt you should worry about this.  It sounds like the engine pulses at idle might be causing a bit of gear rattle...no big deal.  I've heard this many times before.

Thanks Joe, I appreciate the feedback.  

Thanks again Joe.  I think I may have replied in the wrong place last time.

It may be that your throwout bearing is rattling .Just barely push the clutch enough to take up the free play,but not to mash your pressure plate and see if the noise goes away.

Throw out bearing. Very common complaint. A little grease on the input shaft cures it. But, what bear to do it.