It seems like there are a number of different enhancements for A:CWA, but they're scattered throughout the threads. I don't know much about these, but maybe we could put all the enhancements (or even possibly mods?) with working download links into a single place?

I've seen mention here and there of graphic enhancement mods, but I can't quite figure out which ones are for CWA in the alphabet soup of this series. Also, does anyone know of modifications to improve the sounds?

I strongly reccomand you ECP Redux.
It's huge, but its value its immense (I'm using it now, wow).
Two major improvment that might interest everybody:
- different aspect-ratio optimization (16:9 is pretty common nowadays)!
- major graphic improvement: new high resolution textures for almost anything (islands, models...)

You can find it here: ECP Redux

Link leads to a place-holder. Any other sources?

Strange... I used that site just a week ago to download that addon.
In order to be able to download the addon, the site owner required a PayPal donation of 1£ (to cover hosting costs).
I made it, and he sent me by mail a password to login in the appropiate page and I got an high-speed link to download the whole thing (about 1.5 GB, compressed).

I see that the site is now in a "... back soon" state.
I'm writing to the site owner now, I will let you know his response.

Ok, no answer from the site owner and addon author till today.
If you want to grab a copy of the last available version of this addon (v 1.3) send me a PM about it.
I have uploaded a copy on a file hosting site, I can provide you with a link for the download.

-- EDIT (20/08/2013)
The site is online again. I no longer offer the download link.

Agree with above suggestions. ECP Redux completely changes ArmA cwa in every way. A huge graphics overhaul and controls tweaked to perfection. Every aspect of Arma Cwa is improved. Also you get probably over a hundred new missions that were made by the community. Thousand of hours of play.
ECP puts the game pretty damn close to ArmA Gold graphically. It rocks.

Strange to hear that the site was down. if you guys really can't find it I might upload it to Mega (Mega.co.nz)

Also Arma Gold really is a great game that kind of got overshadowed by Arma 2 ..but honestly I may have even enjoyed it more..i found it less buggy. It look s great and to the untrained eye youd never know it wasnt arma 2.

I have been giving Arma 3 a try...it's okay...not really into it yet...bugged as ever and the new update (1.02) made it even buggier (crashed frequently)...also I'm not crazy about the fact that it's hard wired into steam...I know why BI did that but I still don't like it...making Arma 3 dependent on third party software just goes against everything the game was about before.
To my way of thinking B.I. just became like every other big game developer now...that bums me out....but everything before that (all the way up tp Arma 2) is standalone and thats what i used to love about them.