I've seen these and thought that it might be a cool option.  Anyone have links to some sites or advice on where to look?

The site you are refering to is www.professional-ordnance.com
They sell carbon fiber AR rifles and pistols. They are now selling carbon fiber AR uppers for standard lowers.  I have a carbon fiber AR pistol type 97 and I think it's great, I've had no problems with it so far (600 rnds). However, many owners have had nothing but problems with their guns (see Industry Forums and check out Professional Ordnance).  I've also heard their customer service is poor. Bottom line, don't be the first kid on the block to get one. Wait for somebody else to buy it first and post a range report.

From what I understand also (from reading the industry forum) Professioanl Ordanace does not do any warranty work on any upper or firearm that is not bought directly from them. And from what I have heard, most people are sending the unit back two or three times before itgets running well enough to keep. Buyer beware.

Thanks for the info...  I actually had a Prof.-Ord. pistol, but didn't realize that they were the ones offering the uppers.  My pistol was 100% out of the box and I wish I would've kept it.  I just worry about the upper meeting mil-spec and fitting to my Colt w/out gunsmithing.  Anyone else heard anything about these uppers?